Screaming Power Steering Pump

[chika989]

Would much appreciate your thoughts on my situation:

1987 Chevy 3/4 ton pickup 350

I've replaced the power steering pump five times as of today.....four pumps from Advance and the latest one today from NAPA. I've replaced the gear box, new hoses, drag link, stabilizer and tie rod ends (new fluid and bleeding as per mechanic's instructions). The screaming continues!.....not continually but at start up and when the wheel is turned...there is some difficulty turning the wheel.

Don't know where to go from here. I'm no better off now than I was five power steering pumps ago and many man hours as well.

Any suggestions would be much appreciated.

Thanks so much.

[Southcity]

What kind of condition is the power steering belt in? is the tension on it correct and is it aligned correctly?

[Hoods69BadBowTie]

Originally Posted by Southcity

What kind of condition is the power steering belt in? is the tension on it correct and is it aligned correctly?

I was wandering if there's to much tension on that belt maybe? I can't believe you have put that many pumps on that sucks lol!

[lilpoindexter]

Southcity is on the right track...when the pumps fail, what is happening to them? It sounds like the pulleys might be out of whack.

[Goldfinger]

When i blew mine up it would start to seize and squeal check for it slowing down when under load. if its not doing thing tighten the crap out of it till the belt won't deflect

[motornut]

check and make sure it's aligned
they use different spacers with different pumps on different years
does it go away with spray lube?wd40

[chika989]

Hey guys!....thanks for all the suggestions and support.

I've replaced the belt and aligned the pulley......have tried loosening the belt......have tried tightening the belt.....nothing seems to work. :-(
Just picked up yet another pump from Advance and going in for round seven. I'm really at a loss here.......

[Southcity]

Couple of other things to think about:

1. Make sure you are hooking your power steering lines up correctly (send/return)
2. Make sure to prime your pump once installed before starting the vehicle
3. Are there any stress cracks in the mounting areas of the power steering unit and/or pump? specifically the frame mount areas

Any chance you can post a video or some pics of your setup?

[1LowToy]

As I recall in that vintage it was a real PIA to get any leverage to tighten the belt, and it does have to be real tight. Be sure that the width and angle of the bevel of the belt matches your pulleys. If not it's not making enough contact on the V of the pulley and will squeel like a little (well you know). IMO Gates belts are the only way to go.

If belt matches pulleys and are tight, your steering box may not be by-passing the pressure properly on full turns.

I'd be looking for a Gates or GM belt.

[OnDaTrail]

Drain the fluid out of the old pump and check for metal shavings, water, etc.

[vtwinsport]

I second the hose connection check. after that, maycheck the preload on the top of steering box. raise front wheels off ground, (floor jack under each a-arm) then have someone trun steering wheel while you watch pitman arm, the arm should turn as soon as the steering coulumn shaft turns. Tighten preload until it does.
Silly thought, but have you removed alternator belt for check of squeeling alt bearing? Maybe a check on water pump bearing too?

[BLE 'BURBAN]

You never mentioned if you "bled the powersteering system or not when you changed out the pumps/gear box. If you didn't you'll be burning through pumps left and right.
The best way I've found to bleed the air out of the P/S system is;
1. After hooking up the pressure line and leave the return line off the pump leading into a bottle with about a gallon capacity.
2. Fill the reservior with Power steering fluid. Auto tranny fluid will work (DEXRON VI) but actual Power steering fluid is the best thing to use.
3. slowly turn the steering wheel lock to lock with the ignition off and the front tires off the ground just enough to have no resistance. Do this 3-4 times.
4. REfill the reservoir, and hook up the reurn line to the pump.
5. Start the engine and continue to turn the wheel lock to lock and keep an eye on the fluid level as it will go down as the gear box fills up.
6. The Screaming Banshee should start to subside after a few minutes but won't go away completely......YET.
7. Shut off engine, put the tires back on the ground and let it sit for a bit (15-45min).
8. Start it back up and take it for a short drive to see/hear how it feels/sounds.


Good Luck and Have Fun.

[El Chato530]

Originally Posted by chika989

Hey guys!....thanks for all the suggestions and support.

I've replaced the belt and aligned the pulley......have tried loosening the belt......have tried tightening the belt.....nothing seems to work. :-(
Just picked up yet another pump from Advance and going in for round seven. I'm really at a loss here.......

you can also try a GM pressure regulator sometimes aftermarket are not up to OE standards. im sure you no longer have the oe pump due to the core charge so you can transfer it or hit your local wrecking yard.

[jdheff1982]

I bought my 85 C10 the other day and noticed that the whole bracket vibrates bad due to the beefed up 350 (mods listed in sig). Is there anything I could do to decrease the vibrations? I get intermittent PS loss and makes me think I am at full lock when turning left or right.

Thanks!

[jdheff1982]

Never mind, I found a support piece is missing from the driver side of the bracket.