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pas problem at idle


Guest Dibs2k7

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Guest Dibs2k7

Hi all,

 

Hoping someone can give me some clues on this as i have hunted high and low and not been able to solve this niggly issue with my pas.

 

So running a 94 tt 6spd and I've just rebuilt the pas pump due to it making it some lovely noises, it now runs silent and happy except at idle, as soon as i slow the revs like coming to a roundabout or turn i lose pas, and at idle i get no pas at all, once moving the pas runs fine and as it has done normally in the past.

 

I've tried bleeding again but cant see any bubbles unless it just needs a super bleed, only other thing i can mention is when left for a while on startup she will have full pas at idle after driving for a bit thats when it goes away again.

 

So whats been done, all new gaskets and bearing in the pump, full flush of the pas oil and new serpentine belt as the old one was a bit long in the tooth, barring that no other changes have been made.

 

as always any help is appreciated.

 

Thanks

Damian.

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Hi all,

 

Hoping someone can give me some clues on this as i have hunted high and low and not been able to solve this niggly issue with my pas.

 

So running a 94 tt 6spd and I've just rebuilt the pas pump due to it making it some lovely noises, it now runs silent and happy except at idle, as soon as i slow the revs like coming to a roundabout or turn i lose pas, and at idle i get no pas at all, once moving the pas runs fine and as it has done normally in the past.

 

I've tried bleeding again but cant see any bubbles unless it just needs a super bleed, only other thing i can mention is when left for a while on startup she will have full pas at idle after driving for a bit thats when it goes away again.

 

So whats been done, all new gaskets and bearing in the pump, full flush of the pas oil and new serpentine belt as the old one was a bit long in the tooth, barring that no other changes have been made.

 

as always any help is appreciated.

 

Thanks

Damian.

 

Hi Damian, silly question, you did refill it with ATF and not power steering fluid right?

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Guest Dibs2k7
Hi Damian, silly question, you did refill it with ATF and not power steering fluid right?

 

Apologies should have stated that in my original post it was flushed with fresh dextron 3 atf fluid.

 

I have also now noticed that the pulley has a slight wobble to it nothing major but noticeable.

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Guest Dibs2k7
Dextron 3 is the stuff to use so you got it right there.

 

For piece of mind I'd sort the pulley wobble 1st

 

yeah i was planning on sorting it, so i guess my next question is if anyone has one spare for sale?

 

also am i safe going lightweight on all pulleys bar crank? as i can get lightweight from whifbitz but main stealer im looking 3-4 weeks to get one in.

 

thanks again.

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Guest Dibs2k7
How old/what condition is your crank pulley in?

 

i think its original and theirs about 75k on the clock, ive done the tipex test and can see no issues with it so far, im really hoping its just the wobbly pulley or that she hasnt been bled enough.

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Guest Dibs2k7
Dexron II was used from the factory but since then Dexron III has been released and is safe to use, id sort that pulley wobble. Mine dont wobble.

 

thanks for the replies all but im still stumped so, no play in the pulley its just slightly bent, the resevoir is lovely and clean, no frothing in the fluid and its levels are spot on, it literally just boils down to i cant get pas at anything below 1000rpm soon as im moving and the revs are up my pas is spot on.

 

if anyone has any further ideas id be happy to try.

 

thanks again.

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Are you certain you have power assisted steering at all? It'd be kind of difficult to tell if you have or haven't once on the move. So, I'm going to guess you have no hydraulic pressure coming out of the pump which could mean you didn't rebuild the pump properly or the non return valve sticking. I'd check the HP line pressure.

Edited by rider (see edit history)
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Guest Dibs2k7
Are you certain you have power assisted steering at all? It'd be kind of difficult to tell if you have or haven't once on the move. So, I'm going to guess you have no hydraulic pressure coming out of the pump which could mean you didn't rebuild the pump properly or the non return valve sticking. I'd check the HP line pressure.

 

This is the problem, like you i think im lacking pressure, i can happily rebuild the pump again but im not sure what ive done wrong if anything, what confuses me the most is if i had no pressure i cant see how when sitting still rasing the revs is enough to make the steering lighter, tonight im gonna try forcing the pps to always on to give permenant light steering just to see if i do have pressure.

 

A mechanic friend did mention the return valve sticking he's had the before on a different car, can you possibly point me to where the non return valve is or is there anyway to check if its stuck?

 

Again all the help is appreciated i love my car to bits and while im no mechanic i love working on it and trying to understand it.

Thanks

Damian.

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Guest Dibs2k7
What parts did you remove and replace / renew when rebuilding the pump? Have you got the workshop manual covering this?

 

Hi

 

i'm guessing your the Chris that gets talked about when it comes to refurbishing the pumps, lets see

 

all o rings

gasket

bearing

 

and that's pretty much all that was replaced, i do have a power steering trouble shooter PDF file that gives good advice on problems and possible cures which i believe is part of the workshop manual.

 

basically all i can say is no power steering at all when sat still unless you raise the revs enough. over the next few days i'm gonna take the pump off again and check the pressure relief valve and spring make sure everything is good in there, if it is then i'm clueless as to why the pump just doesn't seem to be giving enough pressure unless the revs are up.

 

Thanks.

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You presumably took all the vanes out of the rotor, or maybe they fell out? Did you notice anything about how they should go back again?

 

Any scoring on the housings or the rotor itself?

 

The pressure relief valve is the black thing screwed into one of the ports of the pump itself, to which the pressure hose in turn screws on.

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Guest Dibs2k7
You presumably took all the vanes out of the rotor, or maybe they fell out? Did you notice anything about how they should go back again?

 

Any scoring on the housings or the rotor itself?

 

The pressure relief valve is the black thing screwed into one of the ports of the pump itself, to which the pressure hose in turn screws on.

 

No scoring that i could notice, the vanes did come out yeah and going from all the info i have rammed into my poor head the past few weeks i know they all need to be facing with the slightly curved side outwards.

 

My only thought is the pressure relief valve as like i say sat still if you rev her enough the steering goes lovely and light let the revs drop power steering goes.

 

The only other thing is the minor bend in the pulley but when running its barely noticeable, unless by some unfortunate luck I've got a kinked pipe that i cant see, when sat at idle you can see the fluid moving in the resevoir it's not making a whirlpool or anything but its noticeable.

 

Thanks for letting me pick your brains on this.

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The correct orientation of the vanes catches many out (and scraps loads of pumps...). I won't be the pulley wobble. It just *MIGHT* be the housing / rotor outer orientation is incorrect, but the manual shows how they should go. My bet from what nyou say is either excess wear or the relief valve is stuck a tiny bit open for some reason. Good luck.

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