Question RE: Updating The Wife's 55

[40]

I am wanting to update the wife's 55 Chevy with power steering and power brakes sometime before Spring and thought I'd tap the RRT brain trust.The brakes have previously been upgraded to Front Discs and a dual M/C so probably just need to add the booster but the steering is still factory "Arm Strong".At one point I was leaning toward a "605" conversion but after driving a couple,I think I will opt for the rack and pinion.I am looking at a complete kit from Classic Chevy...but...at $1100 it seems a bit pricey!Just wondering if anyone on board has done this conversion and has any recomendations?Thanks!!

[Rochie]

Daryle,
What don't you like about the 605 pwr steering?? I did my 57 and I love it.  Is it too twitchy for you or is it too easy to turn? If it's the twitchies that get you put as much positive caster as possible into the front end.  You can get offset upper control arm shafts to give you more caster. That will take all of the twitch out of it.  There is a pressure reducer to increase the turning effort as well.  I think it cost me about $150 to switch over.
WAyne

[40]

Wayne....The couple of cars I have driven with the 605 box have both been kinda "Jumpy" and one turned just about as hard as my 55 without power.I have no idea what the allignment specs were.What are you running for a pump....Late 60's GM style??Thanks!

[Rochie]

Daryle,
I'm runing an early 70's pump without a reducer. I was able to get 5 degrees of positive caster without the off-set shafts.  The caster really makes a difference, although my sons say that the steering is too easy as compared to what they are driving. I wouldn't be surprised at all. One drives a Mitsuibishi Eclipse and the other has manual steering, both rack and pinion.
Wayne

[jaybee]

Daryle,

While my car is a LONG way from on the road I've looked into steering issues pretty extensively.  From what I gather it's critical with the 605 to maximize caster, from the factory they came with minimal caster to make "armstrong" parking easier.  Owners that like them mostly seem to report caster up around 5-6 degrees.  Some frames have room for that, some are running tubular upper control arms.  You can dimple the frame just ahead of the front control arm attachment to get a little more without anything hitting.  Supposedly the new Classic Chevy box is more optimal for these cars, and there's another just coming to market (can't recall the name at this time) that's pretty similar.  My guess is they're using a spool valve for a Buick Grand National, Chevy Monte Carlo SS, or something similar that was meant to be driven more agressively than a garden variety Malibu.

Rack & Pinion conversions also seem to be loved by some and hated by others.  The biggest issue seems to be finding headers that will fit.  Some kits also give a lot of bump steer or very large turning radius.  This conversion should probably be shopped very carefully.

I have instructions with pictures for doing this conversion at home, also.

The Chevy Monza and variants used a power booster that will fit these cars, larger boosters can hit the valve covers.

[BFS57]

Hello;
I too have the same thing going on. I put a duel master (already had another duel master)cylinder w/9" duel booster (from Speedway) Man, what a difference! I went from (car already had disc front) stopping like a stock 57 to being able to stop so fast that I could throw myself through the windshield!!
Now to power steering, I don't want the 605 set up. I am looking at a new steering box like the 605 (I think 500) that has recurculating balls or something different This is from Classic Performance Products. The other set up I have been looking at is from Maval. It is a direct bolt in rack and pinion. The reason I like this is the fact the Maval is the company that re-builds racks as well as makes racks. This system has been designed to work properly on tri 5 Chevies with no bump steer.
It seems as though every set up I have looked at (there is lots of them) every one seems to leave you hanging as far as hooking to the steering colum. Many have done this on purpose because many people change to a modern tilt colum and some try to keep the stock colum so judging what you need to connect everything varies.
The only thing I can say is look at all your options and make a decision based on what you want to spend as well as the desired end result you want.
Bruce

[40]

Thanks guys for the great info!The car has a 350/700R combo with rams horn exhaust manifolds and I was wondering about the clearance problem I might encounter with the R/Pinion.As far as hooking the new box to the existing column....I've been told Classic Chevy makes a Flex coupler that eliminates any vibration problem....any experience?I have also been told to use a 670 Box instead of a 605....I'm not familiar...what is the differance?I understand Summit sells Classic Performance products....guess I'll dig out their catalog and have a look....I'll grab my Speedway book as well and have a look at that brake booster mentioned above.I have the disc brake conversion on her car but perhaps too big of a bore on the M/C as the pedal is very hard to push and the car actually stops worse than a 55 with stock manual brakes.Bruce...What size bore M/C are you using...1"?? Again,thanks for the input!

[jaybee]

I have the disc brake conversion on her car but perhaps too big of a bore on the M/C as the pedal is very hard to push and the car actually stops worse than a 55 with stock manual brakes.

Are the stock drums self energizing?  I'm not sure if they are or not but that could account for part of your hard pedal.  It's part of why even relatively small cars come with power brakes today, especially those with 4 wheel disks.

[Rochie]

Daryle,
Your master bore is probably too large,  1 inch or smaller for non power.  I put 2.5 inch rams horns on mine last year to get away from crappy fitting headers and I have no clearance problems with the 605. I used an old style rag joint to connect to the column, but that was before all the new stuff came out.  It works great though.
And Jaybee the car is converted to Non power discs
Wayne

[40]

Wayne...I understand it's quite a job to shorten the steering column when doing the 605 conversion....seems I heard it needs shortened 8"? I have absolutely no welding skill so would have to farm out shortening the column....that is one of the reasons I was leaning toward the rack/pinion conversion....I believe it hooks directly to the stock column???I am nearly certain the bore on the m/c is too large and that is my problem.I'll bet it's a 1 1/8" bore and I'll go with either a 1" or perhaps a 15/16" if I can locate one.

[BFS57]

Hello Again;
I don't know what the bore is, I just ordered the whole set up from Speedway, which included the bracket and miscellaneous hardware. One thing I just thought about, You have to drill a new hole in your brake pedal and it must be in the correct place because when you convert to this power system the brakes get "touchey" I had problems with the amount of pressure because I tried to "fudge" with the linkage and use an old hole. The linkage has to be straight and where it intercepts the pedal is where you need to do the drilling!
Another thing, Do you have a adjustable residual valve going to the rear drum brakes? You need it! It applies the rear brakes first then the front disc brakes. The set up I got from Speedway didn't need any valving to the front disc brakes but required the rear drum brakes to have an adjustable residual valve, which I already had in the car.
It takes some "adjusting" between all the different components as I had a problem with constant pressure heat build up and man, you ain't going no where!! There is adjustment between the booster and master, and adjustment between the rod going to the pedal and booster and 1/2 turns go a long way! It's really sensitive!!!
Hope this helps! let me know, I'm not a guru, I've just been through this event before!
Bruce

[40]

Thanks Bruce...I am well aware of the delicate adjustment of "the rod"....I adjusted it a "little snug" once and locked everything up going down the road....had no idea at the time what the problem was and had the car brought home on a rollback  A very expensive lesson I won't soon forget!! I've been told the new hole in the pedal needs to be exactly 1" below the factory hole. The brakes are pretty easy to do but this steering thing has me a bit confused....the bright side is that I'm still aware that I'm confused....I fear one day I'll be so confused that I won't know I'm confused!!!

[jaybee]

And Jaybee the car is converted to Non power discs
Wayne

Thanks, I got that.  That's why I mention that disk brake cars normally have power assist as well.

[Bruce Dorsi]

Another thing, Do you have a adjustable residual valve going to the rear drum brakes? You need it! It applies the rear brakes first then the front disc brakes. The set up I got from Speedway didn't need any valving to the front disc brakes but required the rear drum brakes to have an adjustable residual valve, which I already had in the car.

Sorry to nit-pick, but your terminology is incorrect, and may be misleading to others.

The adjustable valve going to the rear brakes is a PROPORTIONING valve, not a residual pressure valve.  ....A proportioning valve does not limit the pressure going to the rear brakes, but instead, controls the RATE at which the pressure rises in the rear brake circuit.  .....A proportioning valve does NOT cause the rear brakes to operate before the front brakes.

A RESIDUAL PRESSURE valve should be installed in the rear drum brake circuit.  .....This is a preset,  non-adjustable, valve which is located in the master cylinder, in the combination valve, or a separate valve plumbed into the circuit.  ......Drum brake circuits usually require a 10psi residual pressure valve.   ......This valve helps prevent ingestion of air past the cup-seals in the wheel cylinders when the brakes are released.

A METERING valve, also known as a HOLD-OFF valve, is the valve which prevents the front discs from activating until there is sufficient pressure in the rear brake circuit to overcome the brake shoe return springs, allowing the rear brakes to activate.  .....These are usually preset, and not readily adjustable.

A COMBINATION valve may incorporate a preset proportioning valve, a metering valve, and a residual pressure valve.  .....Many combo valves also include a differential-pressure valve and/or a switch to warn of hydraulic failure in either brake circuit.  The valve will shut-off fluid flow to the circuit with no pressure, such as when a brake hose or line fails.  .....There are several types of combo valves, and not all incorporate all of these functions.

[48ford]

Daryle,
 You can try a ball bearing convertion kit for the idler arm,I have not driven one but it is close to power steering. the kits are sold by casses chevy in chesterfield Ind. or Frank bottle in new york.
You can get all the info over at chevy talk.com in the modified forum,the subject was beat to death some time back.
Russ&Irene