Yeah - I'm in no mood for that kind of mess! mI'm just going to proceed with the pump rebuild.
I was on the phone with Travis of Rennbay about my pump rebuild kit and he pretty much shot down the theory of this being caused by a broken teflon ring inside the rack. His thought was that its sandwiched between 2 washers, so even if it broke, there would not be enough fluid flow to see a total lose of power assist. The only thing he mentioned other than the pump were a couple of spring loaded pressure relief valves in the rack. If those fail, then you get no pressure. But he did think that's unlikely unless you drive for months with no fluid.
Power Steering Not Working but no visible leaks
Pump seals replaced, tested no change. I get some boost turning right and assist turning left.
There is fluid flow through the reservoir at idle.
Pulled rack and the pinion springs are intact.
On the workbench, I did get some fluid coming out the left side of the rack when I was wiggling the pinion back and forth to get it out. Do I need to replace the seal on the left end? It didn’t leak anytime before this.
Thinking I should I put a few psi of shop air through the lines to see if I find any blockage.
Only other thing I can think of is the hose from the reservoir to the pump. It’s less than a year old but I’ve heard of those collapsing under vacuum.
Anyone other opinions?
Thinking the manual rack option might be preferable to dealing with PS issues every couple of years....
There is fluid flow through the reservoir at idle.
Pulled rack and the pinion springs are intact.
On the workbench, I did get some fluid coming out the left side of the rack when I was wiggling the pinion back and forth to get it out. Do I need to replace the seal on the left end? It didn’t leak anytime before this.
Thinking I should I put a few psi of shop air through the lines to see if I find any blockage.
Only other thing I can think of is the hose from the reservoir to the pump. It’s less than a year old but I’ve heard of those collapsing under vacuum.
Anyone other opinions?
Thinking the manual rack option might be preferable to dealing with PS issues every couple of years....
1986 951 - Silicon Valley
-
Tom
- Site Admin
- Posts: 8589
- Joined: Fri Jun 25, 2021 2:04 pm
- Location: Silicon Valley, CA
- Has thanked: 894 times
- Been thanked: 3858 times
- Contact:
Did this happen before? I think you're running out of possibilities. I'd look to drive a de-powered car before going that route. They are kind of a chore at low speeds. Of course, maybe I'm just old and lazy.whalenlg wrote: Fri Dec 19, 2025 9:23 am Pump seals replaced, tested no change. I get some boost turning right and assist turning left.
There is fluid flow through the reservoir at idle.
Pulled rack and the pinion springs are intact.
On the workbench, I did get some fluid coming out the left side of the rack when I was wiggling the pinion back and forth to get it out. Do I need to replace the seal on the left end? It didn’t leak anytime before this.
Thinking I should I put a few psi of shop air through the lines to see if I find any blockage.
Only other thing I can think of is the hose from the reservoir to the pump. It’s less than a year old but I’ve heard of those collapsing under vacuum.
Anyone other opinions?
Thinking the manual rack option might be preferable to dealing with PS issues every couple of years....
I think power steering rack rebuilds are like alternators and starters -- there are rebuilds and then there are rebuilds. I've given up on anything from national auto parts stores after opening a 'rebuilt' alternator and seeing very un-rebuilt parts inside. 944online commissions their own rebuilder -- might be worth a try...So the rack sprouted a massive leak in id 2022. Rebuilt using the Rennbay kit and it was fine. This time is completely different. Its not leaking (ok wasn't leaking before I pulled the rack), just occasionallly gives any assist turning right and nothing turning left.
My 1st 2 cars were manual - a 1974 Capri and a 1973 240Z. Even my wife's 1st car was a manual rack B210. You just have to think about parking differently. Keep rolling while turning!
Right now, I just don't know the root cause of what I'm seeing. Sure - I can redo my work with the Rennbay kit and reseal the rack, but since it wasn't leaking and it's not the pressure relieve springs, I need to look at the rest of the system, which really just seems to come down to the return line from the rack and the line between the reservoir and the pump since the pump seals are now new. Or maybe the metal tubes that are on the rack.
My 1st 2 cars were manual - a 1974 Capri and a 1973 240Z. Even my wife's 1st car was a manual rack B210. You just have to think about parking differently. Keep rolling while turning!
Right now, I just don't know the root cause of what I'm seeing. Sure - I can redo my work with the Rennbay kit and reseal the rack, but since it wasn't leaking and it's not the pressure relieve springs, I need to look at the rest of the system, which really just seems to come down to the return line from the rack and the line between the reservoir and the pump since the pump seals are now new. Or maybe the metal tubes that are on the rack.
1986 951 - Silicon Valley
Just decided that I had time t0day, I disassembled the rack and ordered the Rennbay reseal kit.
Blew air through all the hoses (no issues).
Rack assembly came apart - only odd thing that I noticed is that it wouldn’t pull through all the way. Rather than force it, I pushed the main pinion housing back the other direction and a sliver of thread dropped out (see pic). That was odd. I'll take a close look at the tube threading to see if it might have come from that.
Will also replace the reservoir to pump hose.
Blew air through all the hoses (no issues).
Rack assembly came apart - only odd thing that I noticed is that it wouldn’t pull through all the way. Rather than force it, I pushed the main pinion housing back the other direction and a sliver of thread dropped out (see pic). That was odd. I'll take a close look at the tube threading to see if it might have come from that.
Will also replace the reservoir to pump hose.
- Add Pictures/Files
-
- IMG_3578.jpg (3.41 MiB) Viewed 706 times
1986 951 - Silicon Valley
-
07turbeaux
- Posts: 65
- Joined: Thu Sep 08, 2022 10:00 pm
- Has thanked: 10 times
- Been thanked: 5 times
Tom. What you mean "chunks" ?
-
Tom
- Site Admin
- Posts: 8589
- Joined: Fri Jun 25, 2021 2:04 pm
- Location: Silicon Valley, CA
- Has thanked: 894 times
- Been thanked: 3858 times
- Contact:
Just meant to be on the look out for signs of any gears or internal rack parts that may have broken/shattered, etc. -- i.e., signs of internal mechanical damage resulting in chunks of whatever in the fluid...
Back on the job. Rebuilt the rack and ugh - one side is leaking and it looks the seal was damaged.
Thought I’d recap some of the more minute lessons learned since I’m getting faster at this (unfortunately!).
Rack removal
1 - pull the tie rod end bolts and separate. I left the tie rods on the rack since it’s can be easier to remove them once you have the rack out. Remove the sway bar. Remove the pressure line from the power steering pump and drain the last of the fluid.
2 - remove the bolt/nut holding the steering shaft u joint to the top of the steering gear. It helps to turn the u-joint to where you can see both the nut and bolt looking up from the left side of the car. I was able to remove them with a fixed closed end wrench and either a 13mm socket or a ratchet closed end wrench. When you can see both sides clearly, it’s way easier to work things off. Take the bolt ALL the way out since you can’t get the u joint off if the bolt is still there
3 - tap a large screwdriver or chisel into the u joint gap to loosen/spread it slightly to make sliding it off easier.
4 - make sure to turn the u joint so that the opening points to the left side of the car and the slot is parallel to the rack. This makes it much easier to push up and away from below. Especially with turbos since there is a heat shield above the u joint.
5 - remove the the return line banjo bolt from the steering gear. I was able to get to it with a open end 17mm wrench.
Disconnect the ground wire from the cross member (phillips head screw).
6 - remove the top 2 13mm bolts holding the rack to the cross member. Loosen as much as possible but don’t full remove the other 2 13mm bolts. The left one will need an open end wrench if you haven’t removed the pressure line bracket. Don’t use a ratchet wrench as it might get stuck between the rack and the pressure line. Push the rack forward to separate from the cross member.
7 - try wiggle the u joint up - it’s not likely to come all the way off, but you’ll know if it’s somehow still binding on the steering gear shaft. If the u joint seems to be sliding up ok, remove the last 2 13mm bolts. With one hand holding the rack and the other wiggling the u joint the u joint should slide off and the rack comes out. If the u joint won't come off, put a jack under the rack and then tap the u joint off. I used a large alignment punch, but any straight, blunt object will be fine.
Installation - changed since original post!:
1 - I reinstall without the tie rods to make it lighter and easier to maneuver the rack into place.
2 - have the u joint opening facing the left side of the car. Make sure that the flat side of the steering gear shift is also facing the left side of the car. The lower left 13mm bolt should be loosely in the rack already since its between the pressure line and the rack. You don't want to put that in later because the pressure line will be in the way unless you remove the loop bracket that secures the pressure line to the rack.
3 - put the rack onto the cross member and lightly thread the lower right 13 mm bolt - this allows some movement of the rack so you can get enough clearance to get the return line banjo bolt threaded. I used a jack under the middle of the rack to keep it from falling. With 1 bolt lightly threaded, the you 3 hands to work with.
4 - Install the return line banjo bolt with crush washers. Snug but don't torque it yet.
6 - with the rack still suspended on the jack, you can manuever it back and forth to allow the U joint to slip over the shaft.
5 - slide the 13mm bolt through the ujoint, washer and fasten the nut. Can be torqued to 22 ft lbs after you get everything bolted in. Again, line it up so that you can see the bolt head and the nut in front of you.
5 - loosely insert the other 2 13 mm bolts to the cross member. Start tighten them a bit at a time in sequence so that they seat in the rubber rack mounts correctly. The lower left one needed a crows foot socker because of the pressure line.
6 - torque the retaining bolt for the u joint. I did this once with a crows foot socket. The other time with a 13mm ratchet + extension + socket by reaching behind and over the cross member.
6 - snug up the return line banjo bolt - I used a swivel head ratchet wrench followed by a 17mm crows foot to torque it.
When torquing, make sure to hold the hose so that it doesn’t twist around too much.
7 - reconnect the pressure line to the pump.
Thought I’d recap some of the more minute lessons learned since I’m getting faster at this (unfortunately!).
Rack removal
1 - pull the tie rod end bolts and separate. I left the tie rods on the rack since it’s can be easier to remove them once you have the rack out. Remove the sway bar. Remove the pressure line from the power steering pump and drain the last of the fluid.
2 - remove the bolt/nut holding the steering shaft u joint to the top of the steering gear. It helps to turn the u-joint to where you can see both the nut and bolt looking up from the left side of the car. I was able to remove them with a fixed closed end wrench and either a 13mm socket or a ratchet closed end wrench. When you can see both sides clearly, it’s way easier to work things off. Take the bolt ALL the way out since you can’t get the u joint off if the bolt is still there
3 - tap a large screwdriver or chisel into the u joint gap to loosen/spread it slightly to make sliding it off easier.
4 - make sure to turn the u joint so that the opening points to the left side of the car and the slot is parallel to the rack. This makes it much easier to push up and away from below. Especially with turbos since there is a heat shield above the u joint.
5 - remove the the return line banjo bolt from the steering gear. I was able to get to it with a open end 17mm wrench.
Disconnect the ground wire from the cross member (phillips head screw).
6 - remove the top 2 13mm bolts holding the rack to the cross member. Loosen as much as possible but don’t full remove the other 2 13mm bolts. The left one will need an open end wrench if you haven’t removed the pressure line bracket. Don’t use a ratchet wrench as it might get stuck between the rack and the pressure line. Push the rack forward to separate from the cross member.
7 - try wiggle the u joint up - it’s not likely to come all the way off, but you’ll know if it’s somehow still binding on the steering gear shaft. If the u joint seems to be sliding up ok, remove the last 2 13mm bolts. With one hand holding the rack and the other wiggling the u joint the u joint should slide off and the rack comes out. If the u joint won't come off, put a jack under the rack and then tap the u joint off. I used a large alignment punch, but any straight, blunt object will be fine.
Installation - changed since original post!:
1 - I reinstall without the tie rods to make it lighter and easier to maneuver the rack into place.
2 - have the u joint opening facing the left side of the car. Make sure that the flat side of the steering gear shift is also facing the left side of the car. The lower left 13mm bolt should be loosely in the rack already since its between the pressure line and the rack. You don't want to put that in later because the pressure line will be in the way unless you remove the loop bracket that secures the pressure line to the rack.
3 - put the rack onto the cross member and lightly thread the lower right 13 mm bolt - this allows some movement of the rack so you can get enough clearance to get the return line banjo bolt threaded. I used a jack under the middle of the rack to keep it from falling. With 1 bolt lightly threaded, the you 3 hands to work with.
4 - Install the return line banjo bolt with crush washers. Snug but don't torque it yet.
6 - with the rack still suspended on the jack, you can manuever it back and forth to allow the U joint to slip over the shaft.
5 - slide the 13mm bolt through the ujoint, washer and fasten the nut. Can be torqued to 22 ft lbs after you get everything bolted in. Again, line it up so that you can see the bolt head and the nut in front of you.
5 - loosely insert the other 2 13 mm bolts to the cross member. Start tighten them a bit at a time in sequence so that they seat in the rubber rack mounts correctly. The lower left one needed a crows foot socker because of the pressure line.
6 - torque the retaining bolt for the u joint. I did this once with a crows foot socket. The other time with a 13mm ratchet + extension + socket by reaching behind and over the cross member.
6 - snug up the return line banjo bolt - I used a swivel head ratchet wrench followed by a 17mm crows foot to torque it.
When torquing, make sure to hold the hose so that it doesn’t twist around too much.
7 - reconnect the pressure line to the pump.
Last edited by whalenlg on Tue Jan 13, 2026 8:38 pm, edited 2 times in total.
1986 951 - Silicon Valley
-
Tom
- Site Admin
- Posts: 8589
- Joined: Fri Jun 25, 2021 2:04 pm
- Location: Silicon Valley, CA
- Has thanked: 894 times
- Been thanked: 3858 times
- Contact:
Ug, sorry about the leak (but thanks for the tips). Were you getting power assist despite the leak anyway?whalenlg wrote: Thu Jan 01, 2026 3:43 pm Back on the job. Rebuilt the rack and ugh - one side is leaking and it looks the seal was damaged.
Thought I’d recap some of the more minute lessons learned since I’m getting faster at this (unfortunately!).
Rack removal
1 - pull the tie rod end bolts and separate. I left the tie rods on the rack since it’s can be easier to remove them once you have the rack out. Remove the sway bar. Remove the pressure line from the power steering pump and drain the last of the fluid.
2 - remove the bolt/nut holding the steering shaft u joint to the top of the steering gear. It helps to turn the u-joint to where you can see both the nut and bolt looking up from the left side of the car. I was able to remove them with a fixed closed end wrench and either a 13mm socket or a ratchet closed end wrench. When you can see both sides clearly, it’s way easier to work things off. Take the bolt ALL the way out since you can’t get the u joint off if the bolt is still there
3 - tap a large screwdriver or chisel into the u joint gap to loosen/spread it slightly to make sliding it off easier.
4 - make sure to turn the u joint so that the opening points to the left side of the car and the slot is parallel to the rack. This makes it much easier to push up and away from below. Especially with turbos since there is a heat shield above the u joint.
5 - remove the the return line banjo bolt from the steering gear. I was able to get to it with a open end 17mm wrench.
6 - remove the top 2 13mm bolts holding the rack to the cross member. Loosen as much as possible but don’t full remove the other 2 13mm bolts. The left one will need an open end wrench if you haven’t removed the pressure line bracket. Don’t use a ratchet wrench as it might get stuck between the rack and the pressure line. Push the rack forward to separate from the cross member.
7 - try wiggle the u joint up - it’s not likely to come all the way off, but you’ll know if it’s somehow still binding on the steering gear shaft. If the u joint seems to be sliding up ok, remove the last 2 13mm bolts. With one hand holding the rack and the other wiggling the u joint the u joint should slide off and the rack comes out.
Installation
1 - I reinstall without the tie rods to make it lighter and easier to maneuver the rack into place.
2 - have the u joint opening facing the left side of the car. Make sure that the flat side of the steering gear shift is also facing the left side of the car.
3 - put the rack onto the cross member and lightly thread the 2 lower 13 mm bolts - this allows some movement of the rack so you can get the u joint seated. It if isn’t working, remove the bolt on the lower left side to give you more freedom of movement, but keep the right one in place to bear some of the weight of the rack.
4 - slide the 13mm bolt through the ujoint, washer and fasten the nut. Can be torqued to 22 ft lbs after you get everything bolted in. Again, line it up so that you can see the bolt head and the nut in front of you. I used a 13mm crow foot on my torque wrench.
5 - loosely insert the other 2 13 mm bolts to the cross member.
6 - hardest part is getting the return line banjo bolt inserted to the steering gear. It’s possibly easier to do this before step 3 above, but you may need a 2nd person to hold the rack.
When you are at this step, it might help to tighten the 13mm bolts to the rack all the way. Anyway - I was able to get the banjo bolt roughly into the right position using my flex line magnet. I then slipped the final crush washer on, removed the magnet and threaded the banjo bolt with my fingers. I used a swivel head 17mm ratchet wrench to snug it and then a crow foot 17mm to torque. When torquing, make sure to hold the hose so that it doesn’t twist around too much.
7 - tighten and torque the remaining 13mm bolts to the cross member and reconnect the pressure line to the pump.