Plug power steering pump to bypass it? Pressure question.
- Thread starter DejaVue
- Start date
Racks are usually internally lubricated with grease from what I understand; they do not flow fluid through them like a power steering box.
Wayyyyyy back in the day, on ecomodder, a few people put an AC compressor clutch on their power steering pump. I'm not sure that would be practical here, but still neat.
Wayyyyyy back in the day, on ecomodder, a few people put an AC compressor clutch on their power steering pump. I'm not sure that would be practical here, but still neat.
as noted above steering ratios depend on power steering boost or not, you will need a different steering ratio box for decent effort, + the steering wheel itself aids mechanical advantage, hence big steering wheels in non power steering cars + trucks!!!
Originally Posted by Rand
Not sure how old you are but have you ever tried driving a car with power steering disabled?
Its much worse than an old manual power steering rack.
The power steering rack usually doesnt have near the ratio that a manual one would. Could be a safety hazard.
I drove a steering-depowered car for years, (due to the rack leaking). Parking was annoying, but I preferred the feel on the highway. Depowering it actually removed the numbness.
I'm not recommending most people disable the power steering on most cars. I'm just trying to make the car drivable and avoid replacing something that may break again. And it'll actually be more reliable this way. Plus, my state doesn't have any curvy roads, so being able to turn is unnecessary.
Not sure how old you are but have you ever tried driving a car with power steering disabled?
Its much worse than an old manual power steering rack.
The power steering rack usually doesnt have near the ratio that a manual one would. Could be a safety hazard.
I drove a steering-depowered car for years, (due to the rack leaking). Parking was annoying, but I preferred the feel on the highway. Depowering it actually removed the numbness.
I'm not recommending most people disable the power steering on most cars. I'm just trying to make the car drivable and avoid replacing something that may break again. And it'll actually be more reliable this way. Plus, my state doesn't have any curvy roads, so being able to turn is unnecessary.
Originally Posted by Colt45ws
Because pressure is the result of flow trying to go through a restriction. The pump pushes out X ccs per rev and so if there is a restriction somewhere then it will still try to force that amount of fluid through so the pressure will rise until the bypass opens. In a PS system that restriction is in the PS rack or box. The hose coming out of the pump essentially shows no restriction.
Think of it like a open garden hose just drooling on the driveway, but if you put your finger over the end suddenly the pressure rises and you can spray your plants now.
Well-explained. Thank you. I had been thinking the fluid had reduced pressure coming out of the rack and going back to the reservoir due to the steering rack slowing it down, not that the steering rack is what causes the high pressure (1500 psi?) in the first place due to being a restriction.
Multiple people agree, (thanks, everyone!), so I should just have to source a decently-strong (150 psi?) hose to loop the pump output back to the reservoir. I wonder if the stock reservoir-to-pump hose is even rated for 150 psi.
Because pressure is the result of flow trying to go through a restriction. The pump pushes out X ccs per rev and so if there is a restriction somewhere then it will still try to force that amount of fluid through so the pressure will rise until the bypass opens. In a PS system that restriction is in the PS rack or box. The hose coming out of the pump essentially shows no restriction.
Think of it like a open garden hose just drooling on the driveway, but if you put your finger over the end suddenly the pressure rises and you can spray your plants now.
Well-explained. Thank you. I had been thinking the fluid had reduced pressure coming out of the rack and going back to the reservoir due to the steering rack slowing it down, not that the steering rack is what causes the high pressure (1500 psi?) in the first place due to being a restriction.
Multiple people agree, (thanks, everyone!), so I should just have to source a decently-strong (150 psi?) hose to loop the pump output back to the reservoir. I wonder if the stock reservoir-to-pump hose is even rated for 150 psi.
Reservoir to pump hose isn't rated for much since that hose is under suction from the pump.
Return hose from rack to reservoir is quite sturdy, as is the pressure hose from pump to rack.
In all honesty, I wouldn't worry about the pressure rating of the hose, your issue is going to be sealing at the pressure line/hose joint. Might be worth flaring the end of the pressure line, if you cut that, and putting a barbed fitting on it to help hold the line. Or, you might cut the pressure hose in a rubber section of the line, and use a double barbed fitting there to hold your new return hose.
This method (closed loop, no load, plumb output into reservoir return) has been used by lots of guys who own W220 S-class Mercedes. They bypass the ABC (hydraulic suspension) pump when they replace the ABC with coil-overs. A travesty, in my opinion, but not uncommon. Because the suspension pump and power steering pump are tandem, sharing a housing and drive pulley, you have to keep the ABC pump alive, or you'll lose the power steering pump. No, a regular PS pump doesn't fit on an ABC car, the pulleys and location are different. So, they simply route the pump output into the ABC reservoir and the pumps seem to last for quite a while with that set up. An ABC pump has a higher output volume than a normal PS system, so I don't see a problem with your idea.
Other than driveability of the car afterwards. No way for me to predict how that will work out...
Return hose from rack to reservoir is quite sturdy, as is the pressure hose from pump to rack.
In all honesty, I wouldn't worry about the pressure rating of the hose, your issue is going to be sealing at the pressure line/hose joint. Might be worth flaring the end of the pressure line, if you cut that, and putting a barbed fitting on it to help hold the line. Or, you might cut the pressure hose in a rubber section of the line, and use a double barbed fitting there to hold your new return hose.
This method (closed loop, no load, plumb output into reservoir return) has been used by lots of guys who own W220 S-class Mercedes. They bypass the ABC (hydraulic suspension) pump when they replace the ABC with coil-overs. A travesty, in my opinion, but not uncommon. Because the suspension pump and power steering pump are tandem, sharing a housing and drive pulley, you have to keep the ABC pump alive, or you'll lose the power steering pump. No, a regular PS pump doesn't fit on an ABC car, the pulleys and location are different. So, they simply route the pump output into the ABC reservoir and the pumps seem to last for quite a while with that set up. An ABC pump has a higher output volume than a normal PS system, so I don't see a problem with your idea.
Other than driveability of the car afterwards. No way for me to predict how that will work out...
Originally Posted by Astro14
Yeah, the lines on this do rust out. And as previously posted, the rack is a PITA to replace. Not cheap, either.
So, I wonder if the OP is going to try and drive an older Volvo without PS.
That's the only logical reason for his question.
And it's why I asked mine.
dlundblad - I've also flushed the PS system with CHF 202 and put a Magnefine in the PS return line to keep the rack and pump happy. At 237,000 miles on the XC, and about 190,000 on the T5, the original rack and pump are fine.
If he needs a pump, I would go with an Erie Vovo used unti for about $70. New, they're $400.
For a rack, well, there aren't a lot of good options. OE, as you say, is $1,000. I dislike the quality on A1 Cardone, and on a rack that requires dropping the subframe to replace, a lifetime warranty is worthless. A new part would be my recommendation, unless, ZF rebuilds them directly. Edit: I see that there's a core even on Volvo OEM. so, they're rebuilds, too.
Hmm...
Never heard of Erie Volvo. Thanks.
We need a headlight switch and possibly a driver side door module.
Yeah, the lines on this do rust out. And as previously posted, the rack is a PITA to replace. Not cheap, either.
So, I wonder if the OP is going to try and drive an older Volvo without PS.
That's the only logical reason for his question.
And it's why I asked mine.
dlundblad - I've also flushed the PS system with CHF 202 and put a Magnefine in the PS return line to keep the rack and pump happy. At 237,000 miles on the XC, and about 190,000 on the T5, the original rack and pump are fine.
If he needs a pump, I would go with an Erie Vovo used unti for about $70. New, they're $400.
For a rack, well, there aren't a lot of good options. OE, as you say, is $1,000. I dislike the quality on A1 Cardone, and on a rack that requires dropping the subframe to replace, a lifetime warranty is worthless. A new part would be my recommendation, unless, ZF rebuilds them directly. Edit: I see that there's a core even on Volvo OEM. so, they're rebuilds, too.
Hmm...
Never heard of Erie Volvo. Thanks.
We need a headlight switch and possibly a driver side door module.
Then Erie Vovo (don't ask me why they spell it differently) is your kind of place! I've bought lots of stuff rom them over the years. Always been happy.
Only issue is that the supply of good P2 cars is dwindling...some parts are getting hard to find. Radios, for example.
Only issue is that the supply of good P2 cars is dwindling...some parts are getting hard to find. Radios, for example.
Call these guys they do perfect work and it probably wont cost more than $350.
http://www.jorgenauto.com/rack-pinion/volvo.html
http://www.jorgenauto.com/rack-pinion/volvo.html
Your pump "could" supply 1000 PSI. It won't if it's not connected to a loaded rack. There are little valves inside the rack that demand pressure, but only during turning.
My camry has a little electric switch on the pump to detect high loads so it can preemptively bump up the idle. Just cruising down the highway there's no restriction and the pump just freewheels.
Connect the outie to the innie. Done.
Even at full pressure the stock design returns fluid to the reservoir. The return line has had most of the pressure removed as the job it had to do, is done.
I also worry about the manual-ized rack not being everything you dreamed of. Racks I've seen have standard brake lines on them, maybe you can flare something new or cut the rusty part out and butt something else up with a compression fitting.
My camry has a little electric switch on the pump to detect high loads so it can preemptively bump up the idle. Just cruising down the highway there's no restriction and the pump just freewheels.
Connect the outie to the innie. Done.
Even at full pressure the stock design returns fluid to the reservoir. The return line has had most of the pressure removed as the job it had to do, is done.
I also worry about the manual-ized rack not being everything you dreamed of. Racks I've seen have standard brake lines on them, maybe you can flare something new or cut the rusty part out and butt something else up with a compression fitting.
Originally Posted by Astro14
In all honesty, I wouldn't worry about the pressure rating of the hose, your issue is going to be sealing at the pressure line/hose joint. Might be worth flaring the end of the pressure line, if you cut that, and putting a barbed fitting on it to help hold the line. Or, you might cut the pressure hose in a rubber section of the line, and use a double barbed fitting there to hold your new return hose.
The lines on the car seem good. I'd like to leave the lines (at least for a while) in case I change my mind. Unlikely, but possible. The pressure line is the main one I'm thinking about since that one isn't cheap.
Options may open up once I find out what size of fitting is on the pump's output line, and if the stock fitting isn't weird in some way. After that, should be able to just use a stainless braided hose or similar. If the stock fitting isn't weird, maybe an off-the-shelf braided hose with metric end would work.
eljefino: Yeah, I was about to write maybe brake line would work. Why wouldn't it, I guess. Even an off-the-shelf section of it with ends already on, if the fitting matches up to the pump. And it's nice to have another affirmative on not having to worry much about the output pressure.
In all honesty, I wouldn't worry about the pressure rating of the hose, your issue is going to be sealing at the pressure line/hose joint. Might be worth flaring the end of the pressure line, if you cut that, and putting a barbed fitting on it to help hold the line. Or, you might cut the pressure hose in a rubber section of the line, and use a double barbed fitting there to hold your new return hose.
The lines on the car seem good. I'd like to leave the lines (at least for a while) in case I change my mind. Unlikely, but possible. The pressure line is the main one I'm thinking about since that one isn't cheap.
Options may open up once I find out what size of fitting is on the pump's output line, and if the stock fitting isn't weird in some way. After that, should be able to just use a stainless braided hose or similar. If the stock fitting isn't weird, maybe an off-the-shelf braided hose with metric end would work.
eljefino: Yeah, I was about to write maybe brake line would work. Why wouldn't it, I guess. Even an off-the-shelf section of it with ends already on, if the fitting matches up to the pump. And it's nice to have another affirmative on not having to worry much about the output pressure.
I see. You'd like to preserve the option of future restoration of the system.
Can you get a junkyard pressure line and cut that one?
There is an o-ring in the pressure line - inside the pump. It'll leak without that o-ring. I don't think a brake fitting, or flared line, will substitute...
But take a look and see if that's how it looks to you.
Can you get a junkyard pressure line and cut that one?
There is an o-ring in the pressure line - inside the pump. It'll leak without that o-ring. I don't think a brake fitting, or flared line, will substitute...
But take a look and see if that's how it looks to you.
- Joined
- Aug 14, 2022
- Messages
- 3
DejaVue, another on the Volvo forum send me your post/thread from hear in response to me having a similar issue-----burning out pumps due to leaking rack and not monitoring fluid levels well. I too am interested in this solution of looping the pump and reservoir and leaving the rack out of it. Doubt you will get a notification from this 4 years later but if you do did you do this and has it worked out and any suggestions on me doing that same thing myself ??
Ha, nope, I don't think I got a notification on this. Just happened to log in today and saw it.
As advised, I wound up going to a salvage yard and cutting a foot or so of fitting and line that goes into the PS pump to leave the current line alone in case I wanted to easily reverse this and perhaps fix it properly.
I was all set to buy some stainless braided hose and run it around the engine bay with that fitting, and then the day before doing it I thought hmm, how about giving a stop-leak product a chance. It could make things worse, or it could be a miracle fix.
It was a miracle fix. I was going to post an update, but I rarely drive the car, so it took months to be sure the stop-leak was working. I don't know if it works more on miles driven (getting the fluid moving) or on time. Probably both. It certainly had more time than miles driven. I used the stuff with 205 in the name. There were plenty of convincing reviews claiming it can be magic in a bottle. And this time it was.
As advised, I wound up going to a salvage yard and cutting a foot or so of fitting and line that goes into the PS pump to leave the current line alone in case I wanted to easily reverse this and perhaps fix it properly.
I was all set to buy some stainless braided hose and run it around the engine bay with that fitting, and then the day before doing it I thought hmm, how about giving a stop-leak product a chance. It could make things worse, or it could be a miracle fix.
It was a miracle fix. I was going to post an update, but I rarely drive the car, so it took months to be sure the stop-leak was working. I don't know if it works more on miles driven (getting the fluid moving) or on time. Probably both. It certainly had more time than miles driven. I used the stuff with 205 in the name. There were plenty of convincing reviews claiming it can be magic in a bottle. And this time it was.
- Joined
- Aug 14, 2022
- Messages
- 3
Funny you posting and checking in here, you havent found the Volvo Forums.
Well i did what what discussed and am pretty hopeful I'm going to be good now. Bought a used pump that had been cut off and with a brass joiner i joined with screw clamps a hose section from a washing machine water line ( no braided high pressure hose)----no leaks at the joint and im hopeful this issue is over. I got a year off the first pump replacement after a $500 tow bill breaking down in Alabama on way to Atl. The second replacement pump i planned on filling the reservoir to lube the pump every 100) miles and the pump blew up after about 500 miles within the month ( another 200 tow---i never break down closer to home)
My leak at the rack must have been worse than yours, I had tries some Castrol stop leak so-claimed and it did nothing. Still have the output line there is i ever want to hook it back up and see if it can deal with the leak. Been driving this without power steering for some time and it hasnt been bad at all, only when parking is it difficult. You got lucky with a miracle, i need one too, it threw a p420 catalytic converter code today--------only got about 150M on it but stating to have too many issues though happily not of engine or tranny, knock on wood.
Well i did what what discussed and am pretty hopeful I'm going to be good now. Bought a used pump that had been cut off and with a brass joiner i joined with screw clamps a hose section from a washing machine water line ( no braided high pressure hose)----no leaks at the joint and im hopeful this issue is over. I got a year off the first pump replacement after a $500 tow bill breaking down in Alabama on way to Atl. The second replacement pump i planned on filling the reservoir to lube the pump every 100) miles and the pump blew up after about 500 miles within the month ( another 200 tow---i never break down closer to home)
My leak at the rack must have been worse than yours, I had tries some Castrol stop leak so-claimed and it did nothing. Still have the output line there is i ever want to hook it back up and see if it can deal with the leak. Been driving this without power steering for some time and it hasnt been bad at all, only when parking is it difficult. You got lucky with a miracle, i need one too, it threw a p420 catalytic converter code today--------only got about 150M on it but stating to have too many issues though happily not of engine or tranny, knock on wood.
Attachments
How's the feel without power assist?
- Joined
- Aug 14, 2022
- Messages
- 3
i havent had power steering for quite a while so no change----no issue steering that car at all when moving, only when parking is it an issue but well used to it, not getting a new rack installed on a 20 yr old car
Good to know it worked. I hadn't considered washing machine hose.
Next up: bypassing the coolant hoses on the turbocharger.
Next up: bypassing the coolant hoses on the turbocharger.
