Anyone here ever changed out front brake hoses?

[trentc]

I got a '88 Suburban and trying to change the driver side brake hose out.

I have run into a major problem getting this thing off. The tiny bolt attached to the brake line on the inside of the frame.

I have tried all kinds of tools and cannot get none of them to grab on to it so I can break the fitting loose.


I have tried wrenches (SAE/Metric), Channel locks, locking pliers, adjustable, pliers.

Beside suing GM into bankruptcy for making such a crappy design, I am out of ideas.

Thanks.

Trent

[DmaxMaverick]

That fitting you are trying to remove is probably a rivet. Have you tried to remove the hose at the bulkhead fitting, where it attaches to the bracket?

[trentc]

That fitting you are trying to remove is probably a rivet. Have you tried to remove the hose at the bulkhead fitting, where it attaches to the bracket?


There are no rivets.

The brake hose fitting goes through the frame from the outside. On the inside is the brake line going to the fitting. It has a small bolt/nut which has outside threads. It threads to the inside of the brake hose fitting which completes the connection.

However, there seems to be another nut against the frame on the inside. When trying to turn the fitting, the brake hose starts turning, hence for my need to get a tool that will fit it.

Thanks

[DmaxMaverick]

That's the bulkhead fitting (your first post sounded like you were trying to remove a bracket, which some models have instead of going through the frame). One "nut" is attached to the hose (turns with the hose), and the other side is a threaded fitting with a jam nut. The nut that turns with the hose is only for holding it stationary while you loosen the fitting on the other side. Once the fitting is removed, the jam nut will release the hose from the hole in the frame/bracket.

Don't blame GM for this one. It is a standard bulkhead fitting, used world wide in automotive and aircraft applications for decades. It is much easier to remove/install these, and others, with tubing wrenches. But, once you bugger it up with pliers, you'll have to continue with pliers. You may be better off to cut/chisel it off, at the hose side, which you are replacing, anyway.

[trentc]

I went out and got a pair of smaller locking pliers that have a better gripping mouth. It is on the bolt now snugly, but I am having trouble getting the fitting off. It is a bit stripped now. I can get a good grip on it with a small pipe wrench, but no room to move.

I could probably go out and get that Sears too kit to remove stripped bolts & nuts.

So what you are saying about the jamming nut is that you only need to turn it a bit and will lock the whole assemble into place?

About cutting it off, I suppose I could do that with a reciprocating saw, but I am worried about not getting it out. The thread I have is threaded and If I can't screw it out after that, then I am for sure more screwed.

Thanks

[DmaxMaverick]

I went out and got a pair of smaller locking pliers that have a better gripping mouth. It is on the bolt now snugly, but I am having trouble getting the fitting off. It is a bit stripped now. I can get a good grip on it with a small pipe wrench, but no room to move.

I could probably go out and get that Sears too kit to remove stripped bolts & nuts.

So what you are saying about the jamming nut is that you only need to turn it a bit and will lock the whole assemble into place?

About cutting it off, I suppose I could do that with a reciprocating saw, but I am worried about not getting it out. The thread I have is threaded and If I can't screw it out after that, then I am for sure more screwed.

Thanks

Yes (to the bold part). The jam nut locks the fitting to the frame (AKA: bulkhead), against the fitting/nut on the other side.

Is there any way you can post a pic of what you are working on? I want to be sure we are talking about the same thing. What you describe doesn't sound exactly right.

Anyway, once the hose fitting is cut/broken off of one side (against the frame), the fitting will fall out the other side (maybe with a little help). You could use a saw, but it should chisel out just as easy. They pop right off with an air hammer (chisel bit).

[trentc]

Okay, here are a couple of pictures.
As you can see, there are threads on the outer area.

http://i317.photobucket.com/albums/mm361/tcreek/IMGA1039.jpghttp://i317.photobucket.com/albums/mm361/tcreek/IMGA1038.jpg

[DmaxMaverick]

OK. That big stamped nut is the jam nut. The smaller thread inside the larger thread is the hose fitting. You need to place a wrench on the OTHER side of the frame to secure the fitting, while you loosen the hose fitting. If you try to use a plier on the larger threaded part, it will clamp the smaller fitting thread (and prevent it from loosening). The jam nut only secures the fitting assy to the frame. DO NOT cut the fitting, like I said before. If you do, you'll have to replace both lines. Soak the fitting with some PB Blaster and wait a day or two. It looks like some significant corrosion is at work, which will hinder your efforts. At any rate, the hose (smaller hex) is connected at the fitting in the pic, not the other side. This is not a bolt, but a threaded tube. Ideally, it should come right off, but they rarely do after 20 years.

[trentc]

OK. That big stamped nut is the jam nut. The smaller thread inside the larger thread is the hose fitting. You need to place a wrench on the OTHER side of the frame to secure the fitting, while you loosen the hose fitting. If you try to use a plier on the larger threaded part, it will clamp the smaller fitting thread (and prevent it from loosening). The jam nut only secures the fitting assy to the frame. DO NOT cut the fitting, like I said before. If you do, you'll have to replace both lines. Soak the fitting with some PB Blaster and wait a day or two. It looks like some significant corrosion is at work, which will hinder your efforts. At any rate, the hose (smaller hex) is connected at the fitting in the pic, not the other side. This is not a bolt, but a threaded tube. Ideally, it should come right off, but they rarely do after 20 years.

Can you recommend what tool to use to turn that smaller threaded tube nut? I really do not want to be stripping it.

[Robyn]

Now if your up to some delicate surgery you can use a die grinder with a small cutoff wheel and carefully grind down the material over the actual hard line fitting where it enters the hose assembly.

The secret is not to get crazy here. Worry the fitting down in 2 places on opposite sides so that it is very close to the inner threads. This will weaken the hold on the line fitting.

Use only a tube wrench on the small fitting on the line, else you risk rounding it off.

Once the brake line is clear of the hose assembly carefully move the line to gain some access to the other unit in the frame (Cover the fitting to keep the line clean)

Now you can cut the stamped nut loose and the remove the hose from the hole in the frame.

I have had to do this a couple times in the past. It will take a bit of time but the only thing you loose is the part you want to remove anyway.

A air die grinder is great but a small Dremel will work fine too.

Definately soak the fitting with the Skunk Piss.

Be careful though once you start thing coming loose to NOT allow any of the penetrant to enter the brake line.

Any contamination of the system with this high power solvent can cause issues with the brake calipers internal seals.

Let us know how it goes.

Best

Robyn

[trentc]

I would prefer not to start cutting into this area because the area has so little space to work in and can only get one hand in the area. Once you start working in that area, your site of the area is obscured.


Also, the use of "tube wrench" seems to be a generic label

http://www.google.com/products?q=tube+wrench&ie=UTF-8&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&um=1&sa=X&oi=product_result_group&resnum=1&ct=title

There are numerous devices shown on that link labeled as tube wrench,and none seem to be able to remove that nut.

Thanks for the help.

[Yukon6.2]

Hi
Try the term line wrench.
They look like a box end,with a slot cut thru the box end so the metal brake line will slip thru.Some times the small fitting on the brake line will be siezed to the metal line so be carefull when starting to turn the small fitting.If it is siezed you will have to get the bulkhead fitting loose from the frame,then you can turn the old rubber hose assembly instead of the small metal fitting.After you have the old rubber hose assembly off then you can ussally work the small fitting loose from the metal line,you have to be very carefull you dont twist the metel line .
If you can't get a line wrench and you still cant get the small fitting loose,then you can still get er done by getting the bulkhead fitting loose,using a wrench or visegrips if the small nut is getting striped hold the small fitting while turning the large fitting.
You should be able to break the jamb nut off the bulkhead fitting,they are usally stamped tin and will brake off easyly,then you should have enough play in the line to pull it thru the frame and work on it where you can see it.A big screwdriver or small prybar driven between the frame and jamb nut will usally get it loose or break it.I usally end up doing it this way ,mainly to get the small fitting and line out where you can see it and make sure you don't twist off the metal line.
Hope this helps
Thomas

[trentc]

That term worked better. I see they are widely available. Do you (or anyone else) know what GM used for this nut, if SAE or Metric? Maybe even what size?

It's for a '88 Suburban.

Thanks for the help

[DmaxMaverick]

Craftsman (http://www.craftsman.com) has several options for tube/flare nut wrenches. You can get either combination type or crows foot wrenches, depending on the space you have to work with. Other brands and parts stores offer the same type of wrenches, as well. Your 1988 should be SAE, but verify the size with a standard wrench first. Like Robyn said, you can cut off the hose end sleeve and then get a 6 point socket on the nut. Still, your fittings need to be soaked with PB Blaster before you try to loosen them.

Here's what the the flare nut wrenches look like.

http://s7.sears.com/is/image/Sears/00979554000

http://s7.sears.com/is/image/Sears/00944196000

[trentc]

I was aking about the size because I tried all of my SAE open ended wrenched and none of them fit. I also tried a metric set, and ditto.

Though it is missing the size 9mm, so I am thinking that is it. I am just a bit tired of buying tools that are not helping me get the job done.


Guess I will try a 9m tomorrow and find the PB Blaster and let you know..

thanks

[DmaxMaverick]

I know. I keep echoing the PB Blaster. But, if you don't, you stand a good chance of twisting off the hose fitting. If it does, you'll have to replace the bulkhead fitting, and probably the hard line on the other side. Once you twist off the fitting, no tool will get it out before destroying everything else. PB Blaster is by no means a sure thing, but it improves your chances of salvaging the repair. If you don't use it, your chances of damaging the fittings is at least double. This isn't a sales pitch, but experience speaking. PB Blaster is a unique product, and I've found no other that will do what it does, as quickly. Soak it, and keep it soaked, for at least 4 hours, but 24 hours is best.

Anyway, your wrench should fit it. I don't recall what size it is (been a long time since I've been under an 88, maybe a 9mm), but your standard wrench should fit. 1988 was a transition year (for GM trucks), and anything is possible, even if it isn't. Also check the new hose. It is possible corrosion has changed the size of the old fitting. At this point, I'd suggest cutting off the tubing sleeve on the fitting (on the old one!), and using a socket on it. Ideally, it needs to come out with as little hex-flat distortion possible. A flare nut wrench or socket will do this, and a socket is better. Remember, it's hollow, and probably very brittle at its age. Patience is a virtue, at this point.

[trentc]

I know for sure it is definetly metric because I have already cut the hose off and put on a SAE impact duty socket on it that "felt" as if it was correct size. I gave it a hard turn and stripped the fitting. I have the new hose and it measures to 15 mm. So I guess the other side is 9mm.

I will go ahead and find PB blaster and apply it. Despite what the picture looks like, that area is actually all nice looking bright silver color with no corrosion. It's just got a lot of dirt on it. Seems the previous owners must have lived in a rural area due to the amount of dirt caked underneath.

Well, off to find some wrenches..

Thanks


Add:

Okay..got the PB Blaster from Wally World and applied. It will have at least 12 or more hours to soak.

[trentc]

I read a few other forums about people having some problems with the same thing I am having. They decided to go with putting on a locking pliers on the line nut & socket on the other side, and having successful results. They indicated even with the line wrench, it still felt like it was going to strip the nut.

I have decided to go that route. I have the locking pliers on and a 16mm 3/8" socket on the hose side.

I gave it a hard turn and it won't budge. Before I put on a 1/2" socket driver to give me more leverage to turn, I thought I would get some feedback from others who have done this.

I am asking because I am really afraid to break the weak brake line nut and wonder if others have had to excert a great amount of force of getting it off.

Thanks!

[trentc]

I went ahead and gave it a good turn. The brake hose nut is indeed rounded enough so that the socket did not grip it and slipped.

Anyone got some ideas on a removal tool?

[DmaxMaverick]

Bummer. Your only option left, short of pliers, is a Craftsman "Bolt-Out". You'll have to cut away the crimp on the line so you can get the tool on. The tool is an inverse of an "EZ-Out", and they work. That, and more soaking with some PB Blaster. PM/email me if you are still scratching your head.

[Yukon6.2]

Hi
You still have to get the jamb nut off the inside befor you can turn fitting that goes thru the frame.Once you have that off then you can pull the assembly thru the frame and get it apart.The bulkhead fittlng that goes thru the frame also will not turn in the frame because of a stop incorporated in the way the fitting fits in the frame,some times its six sided like a nut or they have a little slot
Good luck Thomas

[trentc]

Okay, I FINALLY go it off thanks to all you who contributed. The hardest part once I got the broken nut/bolt removal tool on it was the jamb nut on the inside of the frame.


The reason I changed the hose was because the brake on that side was sticking. I changed out the caliper because the large amount of oxidation on it. After changing it, there was some improvement, but still sticking.

Now I have it changed it, no more sticking. I do notice though three more problems. I took it on a mile city trip with lots of braking to test it out. The brakes seen out of timing with respect to applying pressure. Thus the vehicle is now pulling to one side.

Next is the brake light it still on.

Then an after driving inspection reveals the driver side wheel completely cool, while the passenger one is a bit warm. Guess this means I have to change the other side also.

Before taking on a driving test, I had to fill up the reservoir with brake fluid. I notice the stuff I just poured in turn a light brown. I stuck my hand to the bottom and was able to scoop out some sludge. I guess that could be the reason for the sticky brakes.


Ideas where to do at next?

Thanks!

[DmaxMaverick]

Your L/R brakes should be of similar health and age. If you've only replaced "parts" on one side, you should do the same on the other (if the age and condition between them is significant). If one side had a need for overhaul, you can expect the other side to be in similar condition, although it may not yet be showing the signs (whatever prompted you to do the service, in the first place). With dissimilar components, you can expect a L/R braking bias. Still, it sounds like you need to flush/fill/bleed the system to get the "timing" and braking quality up.

[trentc]

Okay, I changed the brakes on the passenger side and the pulling went away, however the brake light continues to stay on. I am starting to think it is the parking brake. When I got this thing, an elastic tie down was tied to it and the steering column. It did not seem to be doing anything so I took it off. Pulling on it does not make the light go out either. Who knows.

I guess I will change the other brake line this weekend.


Thanks a bunch!

[rhsub]

You probably need to reset the pressure differential switch
To do this open a bleeder screw at a rear brake and have an assistant slowly push the brake pedal down until the light goes off, close bleeder screw. If you push to far the switch may go to the other side and you will have to bleed a front brake. For future reference to stop this from happening again when bleeding brakes make sure you to release all the power assist pressure from the system and don't apply exessive pressure to the brake pedal when bleeding brakes
If you have dirty brake fluid the system should be cleaned and flushed
To do this; using a clean suction gun (no petroleom products) remove fluid from master cyl, clean reservior with a clean rag and brake cleans (sparingly), refill master cyl with clean fluid from a sealed container (brake fluid will absorb water from the air if left in an unsealed container), open bleeder screws at wheels and let them gravity bleed until you get clean fluid. You will need to have the master cyl cover on loose for it to gravity bleed, keep a eye on the fluid level. After you have clean fluid, pressure bleed at each wheel to remove any remaining dirty fluid, make sure the light is out and you should be good to go. You will probably need 1 or 2 quarts of fluid to do this
Hope this helps
Good luck :)
Ron

[trentc]

Please explain why the rear would needed to be done if the problem I had was in the front?

Thanks for the tips...so much to do, and so little time.

[DmaxMaverick]

Please explain why the rear would needed to be done if the problem I had was in the front?

Thanks for the tips...so much to do, and so little time.

The pressure differential valve/switch will trip if either the front or rear pressure is beyond the threshold, causing your brake lamp on the IP. Loosening one rear bleeder allows the front pressure to "reset" the switch. This is why it's important to watch the lamp while applying pressure (and stop as soon as the lamp goes out), so it doesn't set the other way (like the rear brakes are failing).

Other than that, if your brake fluid and system is crappy on the front, there's no reason to think it isn't as bad on the rear. Unless it has been serviced recently, it is equally important. Just because they work now, doesn't mean they always will. Preventive maintenance is way better than repairs.

[trentc]

I got the other hose replaced today, and put about a little over 1 quart of fluid through the system to try to get rid of that nasty stuff. The rear brakes were worse with dark brown fluid.


The brakes now perform well as a new vehicle now.

However, the brake light remains lit.
Following the guidance, the light never went out.


What else could it be?

[DmaxMaverick]

Either replace the switch, or "exercise" it with the new fluid. Do this by forcing it from one extreme to the other by alternately opening a front bleeder and forcing the pedal to the floor, then the rear (only one bleeder open at a time). The differential pressure, F/R, will force the shuttle in the valve to its extremes, flushing out any remaining old fluid, and cleaning it up. Watch your fluid level.

If this doesn't work after 3-4 cycles, the switch needs to be replaced.

[trentc]

Thanks for that info.

Looks like I won't have time to do it till this weekend. I am wondering if it is an electrical problem since I am having a dim headlight which power is being drawn off to the high beams, and a disconnected wire under the dash, but I guess that is another thread and section.

Thanks again.

[trentc]

It's the weekend now.

About getting that brake light off; Should I bleed it with the engine running, ON, or off position?

Thanks

[JohnC]

The only thing you want on is the light. It's a shuttle valve that senses pressure imbalance between the two systems. When you have a leak pressure in the good side pushes the shuttle to the leaky side and turns the light on. You are not bleeding it. You need to open a bleeder on the side that was still good and use the pressure in the other (repaired) side to (slowly!) push the shuttle back to the center where the light will go out, then close the bleeder without allowing any air back in. Only a small amount of fluid will need to be bled off. If you go to far the light will come back on and you have to repeat by bleeding the other circuit.

[trentc]

Thanks for the response John, but we already went over that issue.
I am at the point of the light refusing to go out.

[trentc]

The only thing you want on is the light. It's a shuttle valve that senses pressure imbalance between the two systems. When you have a leak pressure in the good side pushes the shuttle to the leaky side and turns the light on. You are not bleeding it. You need to open a bleeder on the side that was still good and use the pressure in the other (repaired) side to (slowly!) push the shuttle back to the center where the light will go out, then close the bleeder without allowing any air back in. Only a small amount of fluid will need to be bled off. If you go to far the light will come back on and you have to repeat by bleeding the other circuit.


My light finally went out, I noticed on Friday. Though now the brakes are screwed up.

I did not notice until I had to do a hard break because someone decided to stop quickly in front if me. I thought I was going to hit them

About the midway point in breaking was the strongest, but once I went past that mid point the breaking power started getting weaker as I got closer to the floor.

I did the master cylinder test which I read about and it passed.

Any guesses?

[trentc]

The pressure differential valve/switch will trip if either the front or rear pressure is beyond the threshold, causing your brake lamp on the IP. Loosening one rear bleeder allows the front pressure to "reset" the switch. This is why it's important to watch the lamp while applying pressure (and stop as soon as the lamp goes out), so it doesn't set the other way (like the rear brakes are failing).

Other than that, if your brake fluid and system is crappy on the front, there's no reason to think it isn't as bad on the rear. Unless it has been serviced recently, it is equally important. Just because they work now, doesn't mean they always will. Preventive maintenance is way better than repairs.


Is that also called the "brake proportioning valve?"

I can't find those except for "universal" ones which I saw run for about $55...yikes!

I wonder if I can clean it out.

[DmaxMaverick]

Yes. Same animal. They can be cleaned, but not much more "service" than that. If a generic valve fits, it should work fine. As long as you have the correct calipers, slaves and MC for the system volume, and the system is otherwise healthy.

[trentc]

Yes. Same animal. They can be cleaned, but not much more "service" than that. If a generic valve fits, it should work fine. As long as you have the correct calipers, slaves and MC for the system volume, and the system is otherwise healthy.

Good and bad news.

I went out and took my time, unlike last time, and did a more thorough job of bleeding the brakes.

Light was still on, and took it for a drive. The softness went away and now the rear brakes are locking up before the front. This definitely points to the brake proportioning valve.

I will try your suggestion of doing to Front/Rear bleeding again.

The better news is that my power steering is functioning better. I guess there was more air in the line than I thought.

Thanks again for the help.

Trent