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View Full Version : PS/PB Goes out at the same time!



LJ
12-30-2005, 11:07
Wow- what excitement that could have been!

I have a 2005 K2500 Crew Cab D/A 4x4. I got in one cold morning, fired it up, put it in drive, drove out of my driveway and attempted to turn left down the street, and found I had no PS- and not only that, but when I put my foot on the brake, no PB! I got it stopped before it hit the curb on the other side of the street, but barely. Put it into reverse and gently backed back into my driveway.

Called Onstar- they got a tech who said my Power steering pump not only controlled the steering, but also the power brakes! They are Hydraulic power assist. Who knew. He said the pump apparently had the shaft break, since the belt and pulley were still spinning away w/o any noticeable problem.

Anyway, the tow truck could not get his rollback to my drive as it was 90 degrees from the street- so I tried to gradually and carefully get it rocked back and forth w/o PS to get out on the street so he could pick me up- and all at once, something broke loose and I had both PS & PB!

I cancelled the tow truck and drove it over to the closest GM garage. They checked it out, and could find no problem.

A week later, it again went out, and they towed it this time. They put a new PS Pump on, and said it was fixed.

Do you guys think it's really fixed, or do I have some other electrical problem?? I can't figure it out. The first Tech said on Onstar I'd probably broken a shaft on the PS Pump- but then it started working again magically. Shafts don't heal themselves.

The mechanic this time said he can't explain why it quit working, and didn't know for sure, but now that it was working was a good indicator it had been bad.

I'm nervous that going down the road it will go out again, and this time I'll be in a turn, going 60 or 70, and can't steer nor stop.... How about it, have you ever heard of this problem??

precision37
12-30-2005, 12:39
Do a search on "Hydroboost". You'll probably find an answer.

DmaxMaverick
12-30-2005, 12:46
While the pump could cause your episode, don't rest easy. There is a high likelyhood your hydroboost unit is the root of the problem, and it may happen again. All PS pump flow/pressure is routed through the hydroboost. I'd insist your dealer replace it as well.

Don't fault the design. They've been in use for over 25 years, both Ford and GM, and are generally very reliable. However, issues such as yours do ocasionally come up.

Roy W
12-30-2005, 15:15
The other day I received a post card from GM saying a Hydroboost recall had not been performed on my 2005. It is recall #05006 and is called the "Hydro Boost Accumulator Recall." Might be worth checking into.

xwing
12-31-2005, 09:34
Mine went out like that when I was standing on the brakes hard one time; it was the "power steering pump" (also does brake hydraulics) which had snapped its pulley driveshaft inside the pump somewhat, so pulley didnt fall off but was not turning the internals.

The shaft necks down inside and it snapped at that neckdown weak point. Suboptimal design IMHO. Pump wasn't exactly cheap.
2001 2500HD D/A

madmatt
01-03-2006, 04:38
one other possibilty is a sticking pressure control valve in the p/s pump which would have came new in the new pump.

LJ
01-03-2006, 14:04
Well, here's an update...

The dealership will check out the Hydroboost, but is non-committal on changing it out. GM won't do anything unless the dealership says it's bad. The recall Roy mentioned does not apply to something like this... it was about cracking due to pressure.

I have an appointment to have it checked out- but they put me off until Thursday a week (12th) cause they were busy, and after all, mine is working for now. I'm telling you, if it goes out before that and somebody gets hurt, there's going to be a lawsuit....

Phil B.
01-07-2006, 02:52
I posted several similar problems about 2 yrs. ago. It only happened to me when the truck had been sitting for several days and never while driving. Like you, the first time I had it towed but it was okay by the time it got to the dealer. I was told there is a check valve in the powersteering (or brake booster?) that may be sticking (?). It hasn't happened in a long time so maybe its worn past this problem...

Good luck,

Phil B.

Kennedy
01-07-2006, 07:01
Just FYI, hydraulic brake/steering follows diesels from the 80's. There is no vacuum to operate a vacuum boost without adding a vacuum pump.