Chevy & GMC Vans

Hi folks,
I'm new to this forum. I bought my Safari last year because I needed a good van to drive down to Florida from Montreal with a Vespa scooter in the back, during my Xmas vacations.
My safari has been very reliable...but about two weeks ago, the steering box went bad.
It was jamming and the steering became very loose. Basicaly in the same time, the PS pump started to make lot of noise and I lost the power brakes.

I found a good gearbox in a scrap yard and did basicaly the same procedures as the previous post on that issue..

After that, I realised that it was impossible to bleed the system, the steering was OK when I was reving the engine, but the was impossible to turn on idle. In the same time, I had the same issue with the hydroboost, (on idle, no brake boost, running the engine, it was OK).

So I replaced the pump which was a real pain to do, but it's done.
I bleed the system (turning left to right many time slowly). I finaly got a steering operated perfectly, either on idle or on the road. However, I still have some issues with the hydroboost.

If the engine is cold, the brakes are OK.
After crusing a minute, I loose the power brake and the pedal goes to the floor.
If in the same time I swing the steering wheel on each side (just like the Nascar cars warming up their tires), then I get the pressure back on the hydroboost.
If I wait on at a traffic light, and I rev the engine on neutral, I will see the pedal raise back in place and I get the pressure back on the hydroboost.

I looks like a bleeding problem.
Don't tell me that I will also have to replace the damn hydroboost also???

Does someone here had a similar problem?

Thanks for the help.

First thing...welcome!

Second...what year is your Safari?

You don't say whether the P/S pump is new or from the salvage yard. If the original P/S pump had a catastrophic failure there could be debris in the hoses that contaminated the replacement pump. It may have also put debris in the hydroboost. The replacement pump could also be bad. There could also be an interior failure of one of the hoses. Hydro boost units are pretty much bullet proof. Other than leaking there isn't much that goes wrong with them.

Hi again!
Thanks for the help!
It's a '97 SLX 2WD..

I installed a salvaged gearbox, but a brand new pump.
I also replaced the two lines that goes to the gearbox, because they were rusted and leaking after the installation of the gearbox. You have to understand that it's a northern truck and with the snow and salt, every single bolt is a nightmare to remove. On my truck, all hyd lines were rusted and jammed.
It's possible that I trapped some debris inside the system.. The only that I can see to clean that, is a complete flush and refill...
any suggestion?
If the Hydroboost fail, what's the symptom?
Is it possible that I just need to bleed the brakes?
I doubt that the problem on the brake system, because when I turn the steering wheel, I get the pressure back on the hydroboost...

Did you put the EVO back in the new pump? At least I think the 97's had the variable pump flow. Other than that I would say it needs to be bled more. And double check the hose routing.

As far as I can remember, I did everything as it was originaly. It was a pain to get room to work on that, but I think everything was fine, it doesn't leak. The steering works perfectly now too. I don't see any problem on the steering side, it's only with the hydroboost.
How can I bleed it more than turning the wheel slowly on both sides.
Do I have to rev the engine too?

I will look through my 98 service manual and see if I can find something. I wouldn't think revving the engine would be required.

According to my FSM, you bleed the system by jacking the front wheels off the ground and with the engine off, slowly turn the wheels from lock to lock all the way at least 20 times. Start by turning full left and make sure the reservoir is at the cold level mark.

I would do a complete flush and bleed and go from there. Make sure the EVO is connected on the pump itself. There is an electrical plug.

Thanks for the info!
I bleed the system with the wheels off the ground, but with the engine running, this time I will tried with the engine off.
Actualy, the truck on the stands and I found two brake lines corroded and leaking. I will fix that before, it doesn't help...

Might explain the pedal dropping away.

Problem fixed!
It was finaly the brake system itself.
I had two lines leaking, I replaced them, then to bleed it, I broke the bleed screws, so I had to change the calipers. I finaly got everything working perfectly.

It has been a chain reaction I guess..
I lost the gearbox, then that damaged the pump. And trying to troubleshoot the system, the two brake lines failed.

In canadian dollars , I got the gearbox for 75$, the two calipers for about 100$, the pump for 115$ and another 100$ of hardware and fluids...
I'm very far away from the original estimate that I got from a little garage who wanted 1200$ for the gearbox remplacement only! (5 hours of labor + 500$ for a rebuilt gearbox!)

Thanks for your help!

AWESOME! =D> Glad you got it all sorted out. This is what we do best here...give help so we all save money doing our own repairs!