What will cause pressure build up on power steering reservoir?
#1
Racer
Thread Starter
What will cause pressure build up on power steering reservoir?
My 2007 Base C6 with 84K is having a problem with building up pressure at the power steering reservoir after DD. The lines on the reservoir are starting to leak and after DD when I remove the reservoir cap a good amount of pressure is released. The steering feels fine and no unusual noises.
Is this a pump problem or rotor valve problem or both? I've only filled and drained the reservoir 2 times. Never done a complete drain and fill of the whole system.
I'm thinking I might have melted something plastic in the rotor valve during my last couple HPDE's causing flow restrictions.
Thanks
Is this a pump problem or rotor valve problem or both? I've only filled and drained the reservoir 2 times. Never done a complete drain and fill of the whole system.
I'm thinking I might have melted something plastic in the rotor valve during my last couple HPDE's causing flow restrictions.
Thanks
#2
Safety Car
Member Since: Nov 2000
Location: Shenandoah Valley Virginia
Posts: 4,549
Likes: 0
Received 27 Likes
on
24 Posts
Had similar problem on my 03 Z06 shortly before the pump decided to self destruct. The pump was puking fluid out around the cap when warm due to excess pressure in the reservoir. Check fluid closely for discoloration and contaminents. Ended up replacing mine with a Turn One pump - problem solved.
#3
Racer
Had similar problem on my 03 Z06 shortly before the pump decided to self destruct. The pump was puking fluid out around the cap when warm due to excess pressure in the reservoir. Check fluid closely for discoloration and contaminents. Ended up replacing mine with a Turn One pump - problem solved.
#4
Tech Contributor
Member Since: Oct 1999
Location: Charlotte, NC (formerly Endicott, NY)
Posts: 40,094
Received 8,928 Likes
on
5,333 Posts
It could be a pump problem. However, it could be a fluid fill issue as well. The fluid expands when it gets hot and on track it really gets hot. How full is your system? I found the only way to keep a good pump from puking fluid out of the reservoir is when checking the cold level to make sure the fluid is a shade below the fill cold line. Once I started doing that I stopped getting PS fluid running down the outside of the reservoir.
Bill
Bill
#6
Le Mans Master
Heat does it, probably from HPDE. I recommend Turn One pump also. It is a bitch to change.
Jim
Jim
#7
Racer
Thread Starter
Thanks for the replies guys. Looks like a power steering pump replacement.
I was looking in the engine bay today and it looks like that ABS unit is going to chew up my hands during replacement My pulley has holes in the face unlike the C5's so that should help a little. I've watched some of Froggy's videos for a little help also.
I really can't complain about this never did any oil changes on the system with 84K and about 20 track days. Only other part replaced has been the engine crank seal under warranty
I was looking in the engine bay today and it looks like that ABS unit is going to chew up my hands during replacement My pulley has holes in the face unlike the C5's so that should help a little. I've watched some of Froggy's videos for a little help also.
I really can't complain about this never did any oil changes on the system with 84K and about 20 track days. Only other part replaced has been the engine crank seal under warranty
#8
Drifting
You may not have a problem at all. Just heat and a bit of pressure.
You will normally build a decent amount of pressure in the reservoir due to fluid and air expansion.
A bit of cap pressure is actually a good thing, it provides some head pressure to the pump helping prevent cavitation which causes even more heat and pressure. Try not to check fluid hot at the track as you actually want that bit of pressure.
Would lay odds your fluid resembles still the color of coco with only 2 fill and drain cycles in 84K? My previous C6 did the same thing but puked out cap all over till I cleaned it out ran Redline and barely touching stick.
Try running Redline power steering fluid. Drain with a turkey baster and refill multiple times till not so dark. Cold line on stick while hot on track barely touching cold. Run normal full line on street to get a larger flush.
You will normally build a decent amount of pressure in the reservoir due to fluid and air expansion.
A bit of cap pressure is actually a good thing, it provides some head pressure to the pump helping prevent cavitation which causes even more heat and pressure. Try not to check fluid hot at the track as you actually want that bit of pressure.
Would lay odds your fluid resembles still the color of coco with only 2 fill and drain cycles in 84K? My previous C6 did the same thing but puked out cap all over till I cleaned it out ran Redline and barely touching stick.
Try running Redline power steering fluid. Drain with a turkey baster and refill multiple times till not so dark. Cold line on stick while hot on track barely touching cold. Run normal full line on street to get a larger flush.
#9
Burning Brakes
another possible consideration
Thanks for the replies guys. Looks like a power steering pump replacement.
I was looking in the engine bay today and it looks like that ABS unit is going to chew up my hands during replacement My pulley has holes in the face unlike the C5's so that should help a little. I've watched some of Froggy's videos for a little help also.
I really can't complain about this never did any oil changes on the system with 84K and about 20 track days. Only other part replaced has been the engine crank seal under warranty
I was looking in the engine bay today and it looks like that ABS unit is going to chew up my hands during replacement My pulley has holes in the face unlike the C5's so that should help a little. I've watched some of Froggy's videos for a little help also.
I really can't complain about this never did any oil changes on the system with 84K and about 20 track days. Only other part replaced has been the engine crank seal under warranty
I've been reminded more than once that the race cars that stay the coolest stay out on the track the longest.
Good luck here
#10
Burning Brakes
I would recommend if you have an older C6 with the short return hose to order the longer hose (same Part Number) (also part of a recall I believe) if will be much easier to reinstall and if your leak is actually the hose or you damage it, will keep you from having to go in a second time!!! Ask me how I know!!!
#11
Racer
Thread Starter
Do any of you know off the top of you head what the total fluid capacity is of the system and is there a filter on the C6 power steering system? I see some of the foreign cars have one on the reservoir supply going to pump.
Bought a 1/2 gallon jug at auto zone to do some more flushing. Too cold out in the driveway right now to be busting my knuckles up on a pump replacement Way don't they put drain plugs on the bottom of the steering rack it would make flushing the system so much easier I think
I'm not leaking out of the reservoir cap just at the hose connections on the reservoir and maybe the pump seal. I need to get some real hose clamps the factory clamps aren't tight enough the hoses can spin on the nipples. I'm hoping a good flush will freshen up the system and loosen up mostly some crude/varnish build up than drain and refill again.
Bought a 1/2 gallon jug at auto zone to do some more flushing. Too cold out in the driveway right now to be busting my knuckles up on a pump replacement Way don't they put drain plugs on the bottom of the steering rack it would make flushing the system so much easier I think
I'm not leaking out of the reservoir cap just at the hose connections on the reservoir and maybe the pump seal. I need to get some real hose clamps the factory clamps aren't tight enough the hoses can spin on the nipples. I'm hoping a good flush will freshen up the system and loosen up mostly some crude/varnish build up than drain and refill again.
#13
Melting Slicks
I know this is from last year.. I am about to put my Z away for the winter next week.... I brought this up a a couple months ago. In my 08 Z. I wonder what is causing a huge pressure build up in my ps system.. Is there a check valve that could be stuck in the pump? I have covered every single part of the ps system and the only leak which becomes a high speed fine spray comes out of the top of the reservoir return line behind the ps reservoir.
I have even put 2 screw hose clamps on the there and the pump still forces fluid out of there under high speed or rpm. What in the pump is causing this? It started not long after a real hard autocross. Which I will not do again. lol The engine hood mat is soaked with ps fluid and of course the mess on the underside of the car as it blows back... just on driver side only.. cant see any leaks from anywhere else. Checked them all and all dry!!
Thanks
I have even put 2 screw hose clamps on the there and the pump still forces fluid out of there under high speed or rpm. What in the pump is causing this? It started not long after a real hard autocross. Which I will not do again. lol The engine hood mat is soaked with ps fluid and of course the mess on the underside of the car as it blows back... just on driver side only.. cant see any leaks from anywhere else. Checked them all and all dry!!
Thanks
Last edited by REDZED2; 10-27-2016 at 06:02 AM.
#14
I had a similar problem this year. The root cause was the power steering cap. It looks like the leak is elsewhere, fluid leaks onto the belt and coats the underside of the hood as well as the front of the engine. A new cap change cured everything, then just for good measure I put a much better cooler that what came with my C5Z. I already have the TurnOne reduced output pump.
#15
Racer
I just replaced my rack (rebuilt by Turn One) and PS pump (also turn one) and the PS reservoir still has pressure after a drive. After each drive I twist the cap off to vent but its always the same pressure release after each drive. Normal? I have no ill effects such as hard steering or noise so curious if i'm being overly cautious.
#16
There is more at stake here than a simple pump replacement or rebuild if this continues. The fluid ends over heating and foaming which raises the level and cavitates the system with aerated fluid which damages the rack and pump. I did all the messing around with fluid levels and hi performance fluids and it continued.
I went the Turn One route. See my link below. I saw FFB's post about PSC before but could never get anyone on the other end of the phone to give me a real answer, so I went Turn One. Maybe FFB can offer suggestions on contacting them. Turn one cost $230...
My similar thread here
https://www.corvetteforum.com/forums...-turn-one.html
I went the Turn One route. See my link below. I saw FFB's post about PSC before but could never get anyone on the other end of the phone to give me a real answer, so I went Turn One. Maybe FFB can offer suggestions on contacting them. Turn one cost $230...
My similar thread here
https://www.corvetteforum.com/forums...-turn-one.html
#17
Racer
There is more at stake here than a simple pump replacement or rebuild if this continues. The fluid ends over heating and foaming which raises the level and cavitates the system with aerated fluid which damages the rack and pump. I did all the messing around with fluid levels and hi performance fluids and it continued.
I went the Turn One route. See my link below. I saw FFB's post about PSC before but could never get anyone on the other end of the phone to give me a real answer, so I went Turn One. Maybe FFB can offer suggestions on contacting them. Turn one cost $230...
My similar thread here
https://www.corvetteforum.com/forums...-turn-one.html
I went the Turn One route. See my link below. I saw FFB's post about PSC before but could never get anyone on the other end of the phone to give me a real answer, so I went Turn One. Maybe FFB can offer suggestions on contacting them. Turn one cost $230...
My similar thread here
https://www.corvetteforum.com/forums...-turn-one.html
#19
Former Vendor
I just replaced my rack (rebuilt by Turn One) and PS pump (also turn one) and the PS reservoir still has pressure after a drive. After each drive I twist the cap off to vent but its always the same pressure release after each drive. Normal? I have no ill effects such as hard steering or noise so curious if i'm being overly cautious.
The pressure in the reservoir is normal. The pressure you are experiencing is created by fluid expansion. When the fluid heats up it expands. When the fluid expands it compresses the air volume in the reservoir creating the positive pressure. There is a relief valve in the cap. It is designed to hold 7.5 psi in the reservoir. The pressure in the reservoir helps to improve intake efficiency and reduce pump intake noise.
Thanks,
Jeff
President of Turn One
#20
Racer
Hello,
The pressure in the reservoir is normal. The pressure you are experiencing is created by fluid expansion. When the fluid heats up it expands. When the fluid expands it compresses the air volume in the reservoir creating the positive pressure. There is a relief valve in the cap. It is designed to hold 7.5 psi in the reservoir. The pressure in the reservoir helps to improve intake efficiency and reduce pump intake noise.
Thanks,
Jeff
President of Turn One
The pressure in the reservoir is normal. The pressure you are experiencing is created by fluid expansion. When the fluid heats up it expands. When the fluid expands it compresses the air volume in the reservoir creating the positive pressure. There is a relief valve in the cap. It is designed to hold 7.5 psi in the reservoir. The pressure in the reservoir helps to improve intake efficiency and reduce pump intake noise.
Thanks,
Jeff
President of Turn One