Chevy & GMC Vans

Hi all, Its been a while since I logged into these forums, being as I am based in England I tend to use the ASUK forums.
Anyways Today as I was leaving the supermarket parking lot I lost all power assistance to the steering as I negotiated a intersection, I paniced and hit the brakes as I was heading for a high kerb, NO BRAKES Either!!!!.
Just missed the kerb and managed to get up on the grass verge away from other traffic.

So the drive belt is OK and tensioned, there are no oil leaks around the pump/hoses/steering column/brake resevior.
The only oil is around the PS resevior lid, and that came whilst trying to position the van on the front drive and yanking like hell on the steering wheel.

Recently I have noticed that the steering had a "DEAD" spot when first starting to turn the wheel, Yearly inspection had flagged idler arms needed replacing soon, so thought it was the wear in these causing the problem, It obviously wasnt that.


Sorry I didnt mention that it is a 93, with a Z code engine

Please anybody have a clue what is wrong and needs replacement.

How's the level of your power steering fluid? May need to be changed and or bled.You may have some air getting in the system.

Level of oil was OK, before and after this problem, It was suggested a few weeks ago that I change the oil in the system, But I really think that this defect is past changing the oil now, I suspect it is more a mechanical problem

Maybe past the point of changing. However, I had a similar problem. I had to bleed the system several times to get all the air out and then I was good to go.The steering was terrible. I thought my hydro booster was shot,it was so bad! But as I mentioned,I added some fluid and had to bleed it several times and all was well. I'd bleed it and it would seem fine,then go bad again.Think I ended up bleeding it 5-6 times before it stopped being a problem. I kept looking for a leak,but the fluid level wasn't going down. Finally got all the air out,haven't had any problems since. Have you ever changed the fluid? Worth trying this first,unless of course you definitely know it's leaking. Sorry if I've rambled on to much,I'm tired! Good luck!

There have been some instances where the power steering pump shaft actually broke. Take the serpentine belt off and check the PS pump pulley. Might just be time for a new pump...and you can put new oil in then.

OK Point taken, I will have a look at the shaft first, I take it that it can shear but still appear to be connected otherwise surely the pulley would have come off/out of the pump.
If this appears to be OK then I will try new fluid and bleeding the system.
The van has 125thou miles on the clock, Ive had it since about 115thou and to my knowledge the fluid has never been changed that I know of.
Can I use ATF in the system?

sundanceuk wrote:Can I use ATF in the system?

I would use power steering fluid.

would you belive that we don't have power steering fluid over here, most all manufacturers use atf?, thats why I asked, i will have to ask at the local GM europe dealership.

The only common item the power steering system and the power brake system other than the belt is the pump. If both are affected one can assume the pump has a problem if there is fluid in the system. If just the brakes you could assume the hydra boost. If just the steering you would look at the steering gear. The pump drives both of these. There should be no need to ever bleed the system unless one or more of the parts had been disconnected.

And make sure you use PS fluid! ATF will ruin the system. Ask me how I know.

thanks lockdoc, I won't ask you how because it sounds very expensive.
I had already figured that the pump was shot because of the same reasoning you gave, must say that this system is very rare on european cars and had the auto club guy very confused, he was looking for a servo with vacuum connections and questioned if it was 2 seperate faults rather than one common fault, Afyter I showed him the chiltons manual he had a better idea but still couldnt fix it (I didnt expect him to, I just wanted to get the van home) So My next question is, How do I remove the pump pulley, it says GM tool # so and so, Well I don't stand much chance of gtting that or its equiverlent over here, so can I use a gear puller that grips around the outside? and what about putting the pulley back on ? Obviously I don't want to beat it with a hammer.

There are two tools required. One for removal and one for install. I don't know of any other way to do the job. A word to the wise....don't let the hammer get anywhere near the P/S pump. The most time consuming part of the job is removing and installing the pump on the vehicle. You can do that part and let a shop just change out the pulley. That will save you some $$$$ and a whole lot of frustration.

OK Thanks for the advice, Seems I was wrong about the Power Steering Fluid and it is available in the UK, Just Ive never had to look for it before.
I now have access to the CORRECT tools to both remove and install the PS Pump pulley, and hopefully I will have a replacement pump soon as well.
Is this pump common to other GM vehicles ?, I will get a remanufactured pump or new but the more info I have about what other GM vehicles it is common with the better for sourcing from UK suppliers.
Again THANK YOU ALL for you help and advice.

you can pull the pulley using a standard "power steering pump pulley puller". It hooks on to the ridge on the pulley right around the shaft then pulls off. To reinstall you basicly just need a 3/8 standard thread peice of reddy rod or a long bolt. This threads into the end of the shaft on the pump. Then put a socket or a chunk of flat bar over the end of the bolt so that it is against the pulley put a nut on and tighten the heck out of it to push the pulley back on. If you end up buying a new pump they come with the tool to put the pulley back on. I found that using a air ratchet to turn the nut I was able to hold the pulley still by hand and tighten the pulley on. I would recomend using a chunk of flat bar instead of a socket as you could push the pulley on too far and then your belt will not stay on. With a chunk of flat bar it will stop pushing when it bottoms out against the shaft of the pump making sure you don't go to far.

Good Luck
Kevin