No power on power rack

[yoshi]

I've changed over to a Mll power rack from a manual. Fitted a type1 GM pump from a working setup on an sbc350. I've filled the pump up & turned the steering wheel from side to side & held it fully locked each way but it still feels like a manual setup! Any tips on bleeding? Is it a bleeding issue? What to try? Thanks

[mr48chev]

When I used to do power steering work every day at work in a dealership I always lifted the front wheels off the shop floor to work the wheel back and forth to work the air out of the system.

I'd check to make sure there are no kinks in the lines both steel and rubber. a restriction in the line can be a big issue.

Also did you use a quality power steering fluid. I lost track of the number of rigs someone had put ATF in the power steering and then had problems with. It functions but doesn't work as well as quality power steering fluid.

I've never had to "bleed" a power steering system, some take a bit longer to work the air out of at first start up but it usually works out easy enough, I have had to add fluid as the level drops though, Once you fill the gear box or rack up the level is usually low in the reservoir.

[yoshi]

No kinks in hoses, I'm using http://www.raceengineered.co.uk/prod...ssion-oil-5ltr

[mphudak]

I don't know if it is related, but MII racks run at a lower pressure then the GM puts out. You run the risk of blowing out the seals on the rack if you don't use a pressure reducer.

[yoshi]

It has this inside where the inlet screws in, the pump was being used with a front clip which is Chevy Monte Carlo as far as I know

[mphudak]

That looks to be correct for a gm pump. The special reducer replaces the part that holds those in.

[tmoble]

Originally Posted by yoshi

I've changed over to a Mll power rack from a manual. Fitted a type1 GM pump from a working setup on an sbc350. I've filled the pump up & turned the steering wheel from side to side & held it fully locked each way but it still feels like a manual setup! Any tips on bleeding? Is it a bleeding issue? What to try? Thanks

You did this with the engine running, right? Pressure is what pushes the air out of the rack and back to the pump reservoir.

[yoshi]

Yes tmoble with the engine running

[dsraven]

does your p/s fluid have a bunch of bubbles in it? usually, when you do a job like this, the air that is inside the rack or box gets displaced back to the reservoir with the natural movement of the p/s fluid. that means it is mixing with the fluid as they are both being sent to the same res. I usually start by turning the steering all the way to one lock, then fill the res, then turn the wheels to the other lock (with the wheels off the ground), making sure the res stays full. then leave it for a few minutes, then turn it back all the way to the other lock again. check the res level. then start it up and turn it lock to lock a few times. ensure the res stays full the whole time. then let it sit for a few hours or overnight to let the bubbles out of suspension in the p/s fluid.next day check/top up the fluid level and run it while turning lock to lock several times again. it may take a few runs to get all the bubbles out of the fluid. I have had systems where it seems like no power steering but once the bubbles are out the system works like it is supposed to. make sure to get the right spring kit for the pump though. it can get a little sketchy at highway speeds if too much boost pressure from the pump.

[yoshi]

Ok thanks, "correct Spring kit"? From where? Thanks

[dsraven]

most places that sell mustangII front end stuff also sell the relief valve kit. try TCI, Heidts, fatman etc. also try summit or these guys.

http://www.speedwaymotors.com/Street...Hose-Kits.html maybe these>> http://www.speedwaymotors.com/AN6-Fi...isplayId=27978

basically the stock gm valve has too large of a hole so it flows too much and the pressure is also too high. it will cause the steering to be "twitchy" especially at highway speeds.

[yoshi]

Would not having that reducer fitted make the steering feel like it's manual? I Had another brief look, I put it on axle stands & turned the steering wheel left to right a few times pausing on full lock. Then I tried it again with the engine running. I can see tiny bubbles in the fluid but it's still not easy to turn the wheel

[mr48chev]

Originally Posted by dsraven

does your p/s fluid have a bunch of bubbles in it? usually, when you do a job like this, the air that is inside the rack or box gets displaced back to the reservoir with the natural movement of the p/s fluid. that means it is mixing with the fluid as they are both being sent to the same res. I usually start by turning the steering all the way to one lock, then fill the res, then turn the wheels to the other lock (with the wheels off the ground), making sure the res stays full. then leave it for a few minutes, then turn it back all the way to the other lock again. check the res level. then start it up and turn it lock to lock a few times. ensure the res stays full the whole time. then let it sit for a few hours or overnight to let the bubbles out of suspension in the p/s fluid.next day check/top up the fluid level and run it while turning lock to lock several times again. it may take a few runs to get all the bubbles out of the fluid. I have had systems where it seems like no power steering but once the bubbles are out the system works like it is supposed to. make sure to get the right spring kit for the pump though. it can get a little sketchy at highway speeds if too much boost pressure from the pump.

Right there is a go to tutorial on working the air out of any power steering system when you put it together.

Keep us posted on what goes on with this. Usually with a GM pump and MII rack the complaint is that there is too much power to the rack and it is overly sensitive to the steering wheel. Rather like getting on a strange bicycle That has no appreciable rake to the fork and never being able to relax while riding as the least touch sends you off in one direction or the other.

[yoshi]

Today I removed the rack & pump to check things over, removing the hoses from the rack I can see fluid is in the rack. I'm gonna check & clean everything reinstall & follow the above

[Hampshire]

Though it's been said - again,you need to reduce the pressure in a GM pump with a Ford rack or you will almost definitely have problems. Either get a pressure reduction kit from Borgeson Universal or they can make a reduced pressure pump for you. I suggest them because they specialize in all things power steering for builds, hot rods, etc., and are well acquainted with the requirements/mods to use GM pumps with Ford racks on Mustang ll front end conversions.

[yoshi]

I cleaned everything up & reinstalled the rack & pump. I followed the above & the fluid level dropped a little. I topped it up, turned the wheel a few times then started the engine, turned the wheel a few times, level dropped a little & there's some very small bubbles, but it still feels heavy. I emailed borgsson asking if I need the flow valve or might there be something else wrong. They replied " try disconnecting the return & turn the engine over to see if the pump is working"

[dwcsr]

Originally Posted by yoshi

I cleaned everything up & reinstalled the rack & pump. I followed the above & the fluid level dropped a little. I topped it up, turned the wheel a few times then started the engine, turned the wheel a few times, level dropped a little & there's some very small bubbles, but it still feels heavy. I emailed borgsson asking if I need the flow valve or might there be something else wrong. They replied " try disconnecting the return & turn the engine over to see if the pump is working"

Just don't be looking into the hose when you do it.

[yoshi]

I did that when I blew into the return on the pump, felt a little go in my eye

[dsraven]

if you have a helper and lots of steering fluid, take the return line off and put it in a catch pan (a tall one for splash back), then plug the hose bib on the reservoir. have a buddy stand by with several open containers of fluid. when you start it up and idle it will take the clean, no bubbles, fluid your buddy keeps pouring into the res, and return air entrained fluid to the container. turn the steering from lock to lock as he pours away. gonna take some fluid for this.

[yoshi]

Ok, chatting with Heidts they have suggested that I fit an inline gauge to see if the pump has already been reduced & the pressure is too low.

[chevyguyase]

Yoshi, Take a large screw driver and attempt to pry the pulley away from the pump, GM pump shafts will break and look good. If the shaft is broken it will slide out easily. Next remove enough fluid so that you can see the turbulence down in the reservoir (fluid being pumped). After refilling the pump, turn to a full turn stop position, turn the steering repeatedly on the full turn stop, you should see the pressure hose jump when it hits full turn if you have adequate pressure. You should also hear hi pressure hydraulic bypassing noises on the full turns. listen carefully to a system that's working to familiarize your self with the noises that I'm talking about. Keep us posted we'll figure this out.

[yoshi]

There don't seem to be any movement from the wheel when I place a screwdriver behind it. A Pressure test shows hardly anything on tickover but increases to only 50 psi when I increase the revs. Should I do the test again without the spring & valve in there?

[mphudak]

I wouldn't remove the spring and valve, they are required for the pump to work.

Here is an article on pump modifications.
http://www.gmtruckcentral.com/articl...rsteeringmods/

[yoshi]

Thanks Mphudak looks like you've sorted out the problem. Looking at a diagram of the pump it shows the spring going in last but the link you sent me you can see the valve through the hole, so i copied the diagram which turns out to be wrong, thanks

[yoshi]

A pressure test showed 1000psi, so after looking at the link above thanks to mphudak I added 2 1/32" shims to the valve & now I have 850 psi & power steering. Thanks all