Running a 605 gear box and original chev pump in my 1961 Impala. Has anyone had any experience with either changing the 'flow valve" or adding shims to the pressure release valve?? [email protected] Thanks Mason
I haven't changed the flow valve or shimmed the release valve but I did buy a pressure adjusting valve from Heidts and added to the 49 Chevy I recently sold. It was too quick and the Heidts valve solved the problem. Only thing I noticed was that at the adjustment I made for driving at highway speed it was more like manual steering at idle.
I put an 800 Saginaw and unknown early GM pump in my 47 Frod truck. It steered way too easy - which made it seem "quick". I had done all the entire install so I knew the ratios were all good so I shimmed the pump by adding 1 shim. IIRC the factory had 2 - .030" shims in mine - I added a third - made a huge improvement. Easy to do - you can get shims from another pump - or just make them if you have a lathe. Now if by QUICK you mean the ratio - that is a whole 'nother kettle of fish. You may want to try a shorter pitman arm. I'm not sure about changing the flow - since I didn't have to do that on mine.
Well since my 61 has this done and this topic came up, what's the favored PS pump to hang on the motor? Just whatever fits or is there a prefered application? Thanks in advance, didn't intend a hijack, thought it to be a good place to find that related info.
Use the flow valve shim kit from Borgenson, it is the correct way to reduce the pressure in the pump. The kit is cheap and comes with full instructions. NEVER CUT THE SPRING.
Here's a link to that Borgenson kit. It wasn't real easy to track down on their website. http://www.borgeson.com/xcart/product.php?productid=1684&cat=0&page=1
From Crankshaft Coalition: Steering "feel" If it is simply too “light”, “soft”, or “over responsive”, you may want to address the flow and pressure differentials between RB and R&P. [edit] Pressure relief valving Most older GM pumps will have a pressure rating as high as 1350 psi. The '82–'94 Chevy S10 has the lowest rating at around 1100 psi. The Cavalier rack was designed for a pressure of ~1,000 psi. You can adjust the pressure with a simple shim kit from Borgeson. The pressure relief valve is located behind the high pressure output fitting on the back of the pump. You may need a small magnet to pull it out of the recess. The shim kit comes with a tool to help with removing the end nut, a new O-ring for the outer fitting, and several shims with a guide on how many shims to use to attain the desired pressures. Basically, adding shims reduces the pressure on the spring, allowing the bypass to open sooner and recirculate the fluid, rather than force it to the rack- thus making the pressure lower. The kit allows for reduction to about 750 psi, suitable for a Mustang II rack, which allows you to get well below the normal range for a Cavalier rack. Reduce the sensitivity to what suits you. In most cases, the pressure reduction valve can be removed and replaced with the pump in the car. Yes, you have to drain and refill the pump each time, but that’s pretty minor. [edit] Flow rate The second adjustment available is flow rate. The flow rate is determined by the size of the hole in the high pressure fitting (the one you took out to get to the pressure relief valve) on the back of the pump. The earlier pumps had an output hole of 5/32". The Cavalier pump has an output hole of 1/8" (approximately 20% smaller). I could not find a fitting with the smaller orifice to fit the older pump (newer GM pumps use metric fittings). Perhaps if you start with a later S10 pump, metric might not be an issue- but this needs to be confirmed first. As an alternative, it was fairly simple to weld shut the orifice in the original fitting and re-drill it to 1/8". Note: The experts contend that reducing the pressure will reduce the amount of assist provided, which can be reduced below factory specs to give it a heavier feel. The system is designed with a variable ratio, that is, it is designed to give more assist the further you turn the wheel, like for parking maneuvers, etc. You can't harm it by providing less than factory pressure. The flow rate seems to be more of a factor in the sensitivity over center, where you really don't need any assist. In any event, both changes were noticeable from the original test drive. High pressure hose fitting from the back of the power steering pump Weld or braze, then re-drill the center hole to change flow rate, not the side hole
"Pressure is Pressure" and "Volume is Volume" Pressure controls how light it feels, Volume controls how quick it turns. The pump should be running on bypass all the time, so if the steering is too quick you need to restrict the flow [ the most flow you'll ever need is "lock to lock" parallel parking at idle] From experience with a few Power Steering conversions using Japanese 16:1 steering boxes, they have little "reel" shaped restrictors in the hoses. [1 on power ,2 on return] These restrictors are hidden where the hoses clamp to the inner fender/chassis. Racers LOVE braided "bling bling" hoses, so they make a mistake of removing the restrictors, then they go chasing their tail modifying the pump and steering box to fix the situation. On my car I reduced the pulley speed to the point where I needed to blip the throttle to reduce a shudder cause by low pressure at idle. My car was constantly in the 5000-7000 RPM range so it reduced aeration of the fluid bypassing in the pump "Run factory hoses to match the pump"
I used the Borgeson shim kit on my 62 Bel air wagon. Ordered a 600 Delphi gearbox from them and I've had nothing but problems with the steering. Three washers were used on the pump and there was already one on there. Mine was a factory ps steering car but all the original stuff was leaking and worn out. Borgeson keeps saying I need more caster but I'm not sure how much more I can get after adding ridetech upper control arms. Can get the car to about 50 mph before its hard to control. When I hit a dip in the road the car wants to take off in either direction.
Bumping this thread as it's got a good post above (Thanks 4Woody!) on the two different approaches to modifying a Saginaw P-series, remote reservoir, pump. One approach focuses on pressure, the other on volume. I'm wondering if the high pressure fittings are cross-compatible between the later Type II (TC) Saginaw pumps and the P-series. I'm planning to use a metric P-series, but want to have lower volume, so I'm hoping to be able to just use a pressure fitting from a Type II pump. They're used on all sorts of cars - even Ford uses that pump after finally giving up on the noisy C2 pump they used for years.
I know old thread... Surprised no one has suggested changing the torsion bar in the box. A stiffer torsion bar will increase steering effort. Another part of tuning the steering. https://www.hotrod.com/articles/ccrp-0901-gm-steering-box-upgrade/
Interesting article. Only problem is, the options discussed there only apply if you're staying in the GM family. I'm looking to use a pump from a Chevy Astro van in a European Ford (Sierra) with a Subaru Brat pickup bed on it. If I find the answer to my question I'll update this thread (unless someone else wants to beat me to it).
Been digging back into this project and found that I had stowed away a ~2001 Saab 9-3 power steering pump (p/n 5061841). This is type II pump which uses flow/pressure fittings which are compatible with the P-series pumps. The orifice on the flow fitting is ~3/32", a bit smaller than even the Cavalier pump mentioned above. The overall length of the pressure relief valve is 1.382" vs. 1.375" for the P-series pump out of the Chevy Astro. I'm going to give this a try and see how it works out.
It works! And it works well! i.e. Not whiny, and not too much assist, which is something I was concerned about since GM power steering is often too over-assisted, so you loose road feel. It think it was the Saab 9-3 volume regulator that helped the most in that regard. Before I forget everything, here's what the build consists of (listed in one place). XR4Ti power steering pump bracket, clearanced for Saginaw pump and adapter horseshoe ~2000 Chevy Astro power steering pump $15 ~2005 Chevy Trailerblazer 4.3 pulley Edelman Power steering pump rebuild kit (p/n 7918) $10 PSC Saginaw pump adapter bracket (p/n PSC-MB03K) $30 Saab 9-3 Pump Volume and pressure fittings (only) XR4Ti Hi-pressure hose - bottom half Saab 9-3 Hi-pressure hose - upper half 3/8" barbed fitting to create new hose $5 40.7" / 1035mm Microgroove belt (p/n's 6PK1035, 407K6MK , 5060407) Technically NOT a stretch belt, but I was able to maneuver it on Volvo Power steering reservoir (small, square black unit)
Not having dune these adjustments i can try and tell you what or how i solved a ps problem for a 62 belair Badically i got a sreering unit off if a 78 lemans i remved the steering box off the 62 i removed the pitnum arm off the lemans unit... i remember turing it 180 degrees and re installing the arm ... i then attached it onto the 62s frame with 2 existing bolts matching.there was a third bolt that didnt match the frame holes but i took a longer bolt and a sawed peice of pipe with a peice of hardend 1/4" inch steel strap which i measued two holes and drilled them into strap to mach with the unused tab and the pipe fitted across effectivly sandwiching the unused tab to the frame by use of the steel strap ,the lemans pitnum arm fit the 62 drag link harmonizer perfectly of course i useď the pump and lines off the 78 lemans
Old thread, but there seems to be a lot of confusion about what "quick" steering is. Quick steering has nothing to do with volume or pressure. It is solely based on the ratio of the steering box, and the length of the pitman and spindle steering arms.
“Quick” steering when using a power steering rack should be called “ reaction time “ of the rack,which is purely a result of flow to the rack. Slowing the pump flow by smaller pulley,smaller pump flow rate(CCs per rev) or mechanically restricting flow to the rack will slow the twitchy feeling of the steering. Pressure adjustment would be all about weight of the front end of the vehicle,size of wheels and wide tyre fitting which would effect pump bypass rate. Mustang 2 steering mods seem to be common if not traditional in this game , this is where the above would come into play. Imho.
Correct you are in spades but this thread is one that brought out more bull shit artists than most. Quick steering/ slow steering is how far you move the steering wheel to turn the rig. How many turns lock to lock. Changing pumps, pulleys or pressure valves or springs changes the effort to turn and can greatly change the feel but it doesn't change how many turns you turn the wheel lock to lock or how far you have to turn the wheel to turn a corner. That is all in the box and length of the pitman and steering arms.
Yup. Pump pressure and flow affect the assistance that is provided to the driver. It is very easy to conflate high effort v. low effort with quickness (or lack thereof). My bad shoulder did to not allow me to parallel park my Falcon with a 22:1 box, and a big steering wheel. I can parallel park it now, with one finger on the wheel, and that's with a 16:1 box, and a small steering wheel. Of course, you can guess which one is the power box.
So are you saying by using a higher volume power steering pump you won’t speed up the travel in a power rack making it react quicker?
Been wrong before and no doubt I’ll be wrong again sometimes, I fully understand the above concept with a powered assisted box but not a power rack. Initial reaction time ( twitchy steering) must be improved with less flow. I must be one of those bull shit artists.
Twitchy is indeed due to too high of pressure or too high a flow for the rack but that doesn't change the number of turns you turn the wheel lock to lock nor does it change how far you move the wheel to make the same turn that you may need to turn the wheel more or less in another vehicle. My 77 Chevy 1 ton flatbed with the 10 ft bed an hoist that put an extra 1500 lbs on the back is extremely light and low pressure steering but you have to turn the wheel a lot more than my 98 BMW that in comparison has heavy steering but is is way quicker lock to lock and you had best pay attention as you don't have to turn the wheel very far to change lanes. The good is the faster you go the more effort it takes to move the wheel and in the truck the faster you go the more you end up herding it as you lose feel of the road. I think that is pretty well what is happening with the op, the box isn't really that quick although it may be quicker than the original box but the pressure is high enough that he doesn't have the feel though the steering that he wants. As far as caster goes on that car you would be hard pressed to get 2 degrees positive caster and keep the camber where it should be. There just isn't that much adjustment on that chassis without making mods to get more caster.
Agree totally, can’t change the ratio lock to lock, but can try and change the behaviour in a torque rod though, hence my comment on pressure and flow(not on powered assisted boxes, just powered racks). recently I helped a friend out working on his mates Chev pickup, Saginaw pump and Must 2 rack, was dangerously twitchy as on the freeway at speed , came back to Hydraulics in my mind. I dropped the pump relief to approximately 780 psi and made 2 brass restrictors to fit into the rack tube ports ,just before the rack barrels .020” if I remember correctly. Putting the restrictors in that position seemed to dampen the torque rod action upstream in the spool which got rid of most of the initial twitchy action. No guru but been in Hydraulics for most of my life so have a little understanding.
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