I have an odd problem that concerns the steering, brakes, and even tranny.

First, my steering has been getting very hard, the truck won't turn the wheels very well unless the vehicle is rolling, and even then it can be difficult

second, my brakes are acting up. They work fine most of the time, but as you begin to come to a stop they seem to lose pressure. The pedal gets mushy and you have to push it another couple inches for it to regain pressure. It always seems to happen at the same time the tranny shifts from 2nd to 1st.

I feel like these things are connected somehow. I know the power steering uses the same fluid as the power brakes, does the tranny use it somehow to? Or how would it affect it?

I changed the power steering fluid about 40K ago. The tank is topped off, I just checked.

Any ideas??

IDK. I had similiar problems except for the tranny thing.

I would flush the PS again. Check out the brakes and suspension parts for wear.

Here's my thought, see if this makes sense to you guys.

I'm thinking maybe my power steering pump is going bad...It makes sense that my steering would be going bad because of it, and I know the power steering pump also supplys the power brakes. Does it do anything to supply the tranny?? If so, I'm thinking when the tranny needs fluid to shift into 1st it starves the brakes of Power Braking fluid (not to be confused with the actual brake fluid). Any one else think that makes sense?

nope if you push on the brake at a stop you have no power streering right i had the same problem

Probaly coinsidance (sp) on the tranny, but the brakes and ps are tied together. the pressure valve is probably sticking in the pump. Other than replacing stuff, you can have the truck running and stab the brake pedal hard to 'slam' the pressure valve. This should make it start working right.

20s suck ass, they are too heavy. I played with this problem until I recently replaced my 20s with H2's and no longer have this problem.

nope if you push on the brake at a stop you have no power streering right i had the same problem

No, I have power steering while hitting the brake.

Probaly coinsidance (sp) on the tranny, but the brakes and ps are tied together. the pressure valve is probably sticking in the pump. Other than replacing stuff, you can have the truck running and stab the brake pedal hard to 'slam' the pressure valve. This should make it start working right.

20s suck ass, they are too heavy. I played with this problem until I recently replaced my 20s with H2's and no longer have this problem.

I'm doubting it's a coincidence with the tranny. I set my Edge up to show me the gear it's in. Like clockwork, every time it goes from 2nd to 1st the brakes lose pressure briefly (unitl I press a little harder)

Is the pressure valve something that can be replaced without replacing the pump?

looks like the whole pump assembly is only $114. I may just replace it and see if that does it. Anyone ever replaced one?

I'm doubting it's a coincidence with the tranny. I set my Edge up to show me the gear it's in. Like clockwork, every time it goes from 2nd to 1st the brakes lose pressure briefly (unitl I press a little harder)

Is the pressure valve something that can be replaced without replacing the pump?

When I pull my travel trailer in tow/haul mode, coming to a stop, the tranny is down shifting and right at the very end the tranny releases. You can feel that 'release' and I have to push the brakes a little harder. it's basically when the torque converter releases and the tranny is not assisting in braking anymore. Now I don't know if it's when the tranny goes from 2nd to 1st or if it's in 1st and the t-converter releases pressure. I never really looked into it, it's just how it's functioned since day one.

How long have you had those 20s on there?? When I had mine, the brakes/steering acted completely different than they do now with much lighter wheels/tires.

The pressure valve can be replaced on it's own, but it will probably be a dealer only item and cost as much as an entire ps pump through an outside vendor.

If you want more hydraulic pressure at the pump, you could do this----

replace the current pressure control valve with P/N 26095470, available from GMpartsdirect.com. This valve will provide additional steering assist during parking lot type maneuvers.

You will have to remove the pump from the engine, remove the pressure line and then the high pressure fitting-- the valve is under the fitting.

Be sure you flush the system with clean fluid.

moved to drivetrain

How long have you had those 20s on there?? When I had mine, the brakes/steering acted completely different than they do now with much lighter wheels/tires.

I've had them for about 2 years, but take them of every winter.

If you want more hydraulic pressure at the pump, you could do this----

replace the current pressure control valve with P/N 26095470, available from GMpartsdirect.com. This valve will provide additional steering assist during parking lot type maneuvers.

You will have to remove the pump from the engine, remove the pressure line and then the high pressure fitting-- the valve is under the fitting.

Be sure you flush the system with clean fluid.

I think I'm going to do this along with a new pump. It may be overkill, but for only $130 it seems like a good idea.

check your hydroboost premis, see if its seeping or misting.

check your hydroboost premis, see if its seeping or misting.

May be a dumb question, but is that the large round "pumpkin" mounted to the firewall?

Yep thats it.