noisy power steering

[zaac]

Ok, on to the next problem. 2000 Silverado 4wd 5.3L.

When its cold out the power steering lets out a loud grown for a second right after start up. Once it even blew off the return line on the steering box. I haven't checked anything yet and was wondering if anyone knows if this is a common problem and where to start? My best guess is something is blocking the return hose or cooler but it only does this when it's cold and been sitting overnight. I can't see why it would freeze. Is there a vent somewhere that might be plugged and not letting out the moisture? I dunno. Thanks for any help...Jack

[jdmccright]

No it's not common. Groaning usually means it is low on fluid, but if there is damage to the steering box, the pump has to work extra hard and cold weather makes things even stiffer. Could be a valve sticking from the cold weather. If the fluid looks dark and nasty, try flushing it out along with any crud in there. Keep it topped off to help expel any entrained air.

The burden on the pump can be lessened by allowing the truck to roll very slightly when you have to turn severely...turning the wheel with the truck at a stop causes the pump to have to overcome the tire's standing friction.

Hope this helps!

[j cAT]

Originally Posted by zaac

Ok, on to the next problem. 2000 Silverado 4wd 5.3L.

When its cold out the power steering lets out a loud grown for a second right after start up. Once it even blew off the return line on the steering box. I haven't checked anything yet and was wondering if anyone knows if this is a common problem and where to start? My best guess is something is blocking the return hose or cooler but it only does this when it's cold and been sitting overnight. I can't see why it would freeze. Is there a vent somewhere that might be plugged and not letting out the moisture? I dunno. Thanks for any help...Jack

suck some power steering fluid out and compare with new..if its looking bad replace all fluid ....

I replaced my fluid 2 years ago and it was easier to steer and noise was less...

[zaac]

I changed the fluid 3 months ago and it is full. It groans at start up so there is no turning involved. Looks like I have another not so obvious problem. I hate them ones!

[j cAT]

Originally Posted by zaac

I changed the fluid 3 months ago and it is full. It groans at start up so there is no turning involved. Looks like I have another not so obvious problem. I hate them ones!

It looks like you may need a new pump....and you won't be one of the few...as these pumps do fail like this...

another possibility is the pully shaft seal has a small leak then on start up noise is created until fluid is dispersed...if it does have a leak here try a power steering fluid stop leak product ..I have had great success with this.

[zaac]

Originally Posted by j cAT

It looks like you may need a new pump....and you won't be one of the few...as these pumps do fail like this...

This could be but I don't understand how it could be the pumps fault for blowing off the return line. The pump is pumping all the time whether you're turning or not and when you're not turning I believe the fluid should be pumped freely through the control valve and pressure should stay low. For some reason it pressures up when it shouldn't and that's why I suspected a restriction in the return system or maybe it could be the control valve. Seems weird though that pressure would build up enough to blow off the return line when the pump has a relief valve unless the oil was just to cold for it to work fast enough. Either way it shouldn't pressure up when I'm not turning the steering wheel and I can't understand how the pump is at fault for this. Does this make any sense to you?

Originally Posted by j cAT

another possibility is the pully shaft seal has a small leak then on start up noise is created until fluid is dispersed...if it does have a leak here try a power steering fluid stop leak product ..I have had great success with this.

I'm fairly certain there's no leak and the noise is from high pressure not lack of fluid. I'm not trying to argue with you j cAT, just trying to understand the system better. I've changed the wrong part to many times. What ya think?

[j cAT]

so the pump when cold makes a noise like you have the wheels turned hard left/right...then after a little warm up it quiets down ?

then that would be possibly contaminated or incorrect P.S. fluid...

what type fluid did you use ?

on the back of the P/S pump is the control valve...if this valve sticks this could occur...the reason it sticks may be excessive scoring/wear...

when the hose blew off, it would be correct to raise both wheels off the ground and add fluid to res. while slowly turning the steering wheel to properly fill system without damaging the pump...so it is very possible that the system needs draining and flushing as a possible aid in stopping this pressure problem..to remove any particles .....

if the wheels are turned when on the ground, with low fluid you will damage the pump....

so what's up ?

[zaac]

Originally Posted by j cAT

so the pump when cold makes a noise like you have the wheels turned hard left/right...then after a little warm up it quiets down ?

then that would be possibly contaminated or incorrect P.S. fluid...

what type fluid did you use ?

It's just an initial blast of high pressure like when the wheels are turned fully and then quiets down after about 1 second. I used Prestone P.S. fluid for GM vehicles.

Originally Posted by j cAT

on the back of the P/S pump is the control valve...if this valve sticks this could occur...the reason it sticks may be excessive scoring/wear...

I thought the control valve was in the steering box where the steering shaft connects. Still learning!

Originally Posted by j cAT

when the hose blew off, it would be correct to raise both wheels off the ground and add fluid to res. while slowly turning the steering wheel to properly fill system without damaging the pump...so it is very possible that the system needs draining and flushing as a possible aid in stopping this pressure problem..to remove any particles .....

if the wheels are turned when on the ground, with low fluid you will damage the pump....

All I did was leave the truck in a warm shop overnight and the next day reconnected the return hose with a screw type clamp instead of the OEM spring type so it couldn't blow off again so easily and then refilled with P.S. fluid. When I started it up it groaned again for 1 second and then everything was back to normal. I think I will flush out with P.S. fluid from the dealership. I didn't have this problem last year with the original fluid. Truck now has 180k kilometers so I figured the P.S. fluid was overdue. Guess if it ain't broke I should leave it alone.lol

[j cAT]

[quote=zaac]It's just an initial blast of high pressure like when the wheels are turned fully and then quiets down after about 1 second. I used Prestone P.S. fluid for GM vehicles.

I have used this same fluid with no problems.....try another P/S flush...but lift both front wheels off the ground...remove the return hose and drain and refill...turn wheel left and right to circulate the fluid....when filling...

don't want air bubbles in fluid...

[zaac]

Originally Posted by j cAT

I have used this same fluid with no problems.....try another P/S flush...but lift both front wheels off the ground...remove the return hose and drain and refill...turn wheel left and right to circulate the fluid....when filling...

don't want air bubbles in fluid...

Ok, I'll have time on Thursday. I'll let you know. Thanks again.

[zaac]

Didn't have time on Thursday but Friday and Saturday morning were both -28 C and it didn't make any noise for some reason. I don't have time to fool with it right now so I'm gonna leave it and hopefully it won't come back.