Anyone here ever changed out front brake hoses?

[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