The Stovebolt Site Forums The Parking Lot Tons 'o Fun 1 Ton dual reservoir master cylinder?

I've done some digging but haven't really found anything...

my master cylinder is shot. i figure if I'm going to replace it i may as well go with a dual reservoir. I'd like to stick with the frame mount and plan to stay with the drums all the way around.

anyone know of a good source either from a parts store or even a vehicle i could salvage 1 from?

1954 chevy 3800

thanks,
Tj

Use one from something with a similar bore diameter and with drums or disc same as you have.

That's what I was thinking but I was hoping someone out there had already done it and could tell me a good truck to steal one off of or look up when I go in the part's store.

I imagine there aren't too many trucks that used larger bore side mount dual reservior units out there.

Bore is 1.125" correct? (I know-I can measure...)
Was master cylinder the same from 1/2 ton through 1 ton?
Do I need to try and match up stroke as well or is it not very important?

Thanks!

This should have the information on bore and travel: http://chevy.oldcarmanualproject.com/chevyresto/54140.htm

I found some dual reservoir master cylinders at this site a few weeks ago, but I have never bought one:
http://www.classicpartsusa.com/category/1954_Truck_Parts_Brake_Master_Cylinders/1

Nice! i didn't know the manual had that much detail about brakes! they don't make the books like that anymore do they?

I also didn't know you could get a booster on the bigger trucks.


Tj

do you think if you added residual pressure valves you could get away with a smaller diameter bore on the master cylinder to increase hydraulic advantage while still having enough pedal travel/fluid volume?

would a 10 lb pressure valve actually keep the pads riding close to the drums or do they still release enough to close the wheel cylinder?

Sounds like you want a later model MC with attached booster.
The original booster, a hydro-vac, is mounted on the frame under the passenger's seat and only works with a single circuit system. possible but not practical to use two for a dual system.

There's no substitution for volume, the wheel cylinders need so much fluid and the only way they get it is with he appropriate bore and stroke MC, residual valves don't give you any more fluid.

Drum brake systems usually have a residual pressure valve as part of the MC or proportioning/junction block, usually 10 lb.
Disc brakes can use a 2lb residual pressure valve if MC is lower than the caliper.

what is your opinion on booster? i haven't gotten to drive the truck and see what it's like seeing as I HAVE NO BRAKES

i've read some that seem to sware by the need and others that say stock components in good working order are fine.

i was originally planing on a dual reservoir with no power but as long as it doest make the brakes too sensitive, i don't see why i shouldn't try and squeeze in a booster if i can???

I also wonder if the system could benefit from a proportioning valve as the stock values don't really bias the brake force to the front. I would think that alone would be a big improvement.

I drove and used my 52 1 ton essentially stock for several years and had no complaints with the brakes, they work just fine, and no booster.

Later I swapped to disc brakes and a hydrobooster, having said the stock brakes were fine the new brakes are superb, stops very quickly with just a light tap on the pedal.

It's up to you if you want stock, or to change everything, or something in between the two.

Grigg

I just redid all of my brakes and kept everything stock. I have been driving around the past 5 weekends (max 45 mph) and I have not had a single problem with brakes, except for a little squeaking.

In the future I plan on doing some work to get highway speeds, and at that time I will probably put disk brakes on for safety.

For right now I just wanted something I can cruise around in. I just make sure to give myself some extra room when I am stoping. I would hate to see what a 1 ton would do to the rear end of a Prius.

There are dual masters made for the 1/2 tons that have boosters. They are made to fit in the original location, probably with a special bracket. They use what looks like dual chambers on the booster that are smaller in diameter. I don't know if they sell one for the 1 Ton.

My 51 a Ton has the original type brakes and they work very well. The one problem is that the back brakes are much larger and create a proportionally larger force than the fronts. This is not a problem on dry pavement but on a wet surface it can be. I have thought of adding a proportioning valve and I might do so because I don't carry loads.

we don't have an easy solution for front discs on an AD 54 1 tom do we?

If we do... i"ll likely go that route and find a way to do a power booster...

No, not real easy. So far this is what I have come up with but it will result in a track width 7.35" wider than an original AD 1 ton. some wider is OK, there's room, but that's probably to wide to use original wheels. wheels with a little more back spacing will help and might make it all work out.
https://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=725071#Post725071

Others have tried and some completed swapping rotors to original hubs and fabricating caliper brackets. So there are other options.

Grigg

i think last time i was considering it i found a truck (dodge?) with a strait axle only a fraction of an inch longer. i was thinking i could swap in a strait axle and lift the truck 4" or so... hmm

Tj

Hey TJ, do a google search they are out there without booster. I installed one on my 49 1 ton, when I get to the garage I'll get the info on the one I used. The mounting bkt ($99) was more than the master cylinder ($49). This link is just from a web search I did. Hope this helps.

http://www.mbmbrakeboosters.com/ind...ory_id=10&option=com_virtuemart&Itemid=6

thanks. i'd like to see the info on the one you used. i've seen the brackets you mentioned. seems expensive for what it is but maybe not worth the time to design and fab one for $99. i wonder how critical the dimensions are, if they're not that bad, maybe i'll give it a stab.

This is where I got the bracket

http://www.ecklerstrucks.com/chevy-truck-dual-master-cylinder-adapter-bracket-1947-1954.html

Can't yet find the box of the MC but I know it was Cardone brand. I will post p/n when I find the box or paper work.

That would be awsome. I can get cardone from NAPA. The had no match in the computer but I asked what brands they carry if i can dig up a part number and cardone was one...

so that bracket does work well on a 1-ton?

strange master cylinder

How about this one? same bore. idk about stroke. looks like it even has side mounting.

Anyone wanna explain the difference between "shallow hole" and other types? Is it the plunger style?

The bracket is very nice, thick and heavy. Comes with push rods for chevy and ford apps and mounting hardware. I looked again today and can not find the box the MC came in, sorry. Cardone's web site really does not give good specs on their items. I've found better specs on cardone products on their dealers web sites then their site. The MC is a universal for everything from Buicks to trucks. I know cardone 13-1505 is 1 inch bore.

thanks for looking. maybe ill give them a call or find a dealer to call. may even just give the specs to Napa and see if they can find anything.

Tj

I bought a bracket from Ghostrider on the hamb board. The bracket was very nice and bolted on in stock spot. I then used a 1969 L88 big block vette master cylinder ( cam was so big it was not set up for power brakes- no vaccum).I put disc on all 4 corners of my 3800 1 ton pickup. I used 1996-2002 F250-350 ford rotors- they slip over the studs on the front. Made the front brackets for the caliper - 1985 up 3/4 ton. - Back rotors -( 3/4 ton 85 up 4WD mounted to the back side of the factory hubs- yep even used the stock studs.( black bird interprises makes a kit for rear brackets- 99$) -cut off one corner and it slides over the rear axle tube mount inside the outboard housing flange and grind weld -chamfer the bracket so it bolts up nice and flush- uses three bolts to mount.I did use stock hubs and bearings - and the bonus -you lose about 40lbs per wheel - when you lose the backing plates and brake hubs.
have photos of the front - but not off the back =- but i might get some - can text / or email pics
LMD

Photos please. That sounds like an awesome mod. Trying to keep mine as stock as I can, but definitely interested in making safety upgrades as prudent. jongersbach@yahoo.com is my email for photos. Thanks

On the way - I even took some of the rear set up - today - here is your Xmas gift.Ghostrider is also on this site as well. He makes a fine MC bracket.

LMD

this sounds awesome! wonder how much you have in parts. i imagine i'd buy new rotors but prob can find some salvange calipers... this would solve my problem of master cylidner AND get me disk brakes...

i wonder how braking effort would with no power assist on disk brakes for a 1-ton.

The front rotors were about 70$ each(1996-2002 F 350 - yes I know its a ford rotor - but it let me drill for big studs and not do any machine work and it cleared everything) - highest part of the deal. The calipers - were around 15$ each -with exchange.I used the same caliper on all four corners. - not worth the risk - I bought 4 new / reman. calipers- the brake lines are the same way- ( the flex units - and yes you need flex on all 4 corners- My figures - seals , lines etc -put it at about 120$ a wheel.
I use normal foot pressure and it stops on a dime - I can run up to a red light like all the other idiots and scare the crap out of them because they think it wont stop. If I really grab it - nose to dash. used a speedway proportioning valve just to make sure I could adjust if needed- and the speedway residual valve - both front and rear since the master cylinder is still under the floor.
Mitch

Get the aftermarket mounting bracket from Ecklers.
Use 1976 Corvette master cylinder, will work fine with 1.25" bore wheel cylinders on drum brakes on a 1 ton AD Chevy. It has a 'deep' hole which is what you want for manual brakes. "Shallow" hole is for power brakes.

my understanding is that for 76 vette power m/c is 1-1/8" and manual is 1". figured power would be perfect even if one reservoir is a bit smaller or each reservoir is slightly different in size...

are they 1.25'?

yes, use the power m.c. It is 1.25" bore. It's for disc brakes , but works great with the drum brakes on your 3800.

Every one i find says 76 vette m/c is 1.125 for power brakes. i think this is still ok though becuase original was 1.125

Tj

Napa part # NMC M1974 master cylinder for power brakes. 1.125" bore. The large chamber is for the front brakes. I put this in my '48 3800 truck that has '54 3800 front and rear axles. The push rod hole on the m.c. is deep just like the manual m.c. This is the set up I've had in my truck for 6 years, daily driver. Works great, and NO residual valves, it stops on a dime.

Hmm. No residuals? I was planning on them... For $15 buchs each aren't they worth it?

Tj

Some/many master cylinders come with residual pressure check valves built into them, in which case external ones would be unnecessary/redundant.
Then in some cases you don't need them any how.
I'd like to find a book on brake systems with all this explained... There is way to much rumor and misinformation floating around on the net about brake systems... just hope I'm not adding to it.

Grigg

Yea ive been trying to find a way to figure out if that one has them built in but no luck so far.

Trial and error is probably what will satisfy each individual case.
From my experience, I have not used residual valves. I have a '54 3800 Chevy panel truck that I put Power brakes in 23 years ago, no residual valves. The booster and Master are located in the orginal under floor location. The truck stops on a dime and the pedal feel is excellent, like a brand new truck.
I have a '54 3800 Chevy rack body that put the Corvette master in with the residual valves, and had a very hard pedal and stopping power was poor. And , no I didn't have the residual valves in backwards. I actually tried 3 different sets of residual valves from different manufacture and they ALL were poor.....so I removed the residual valves and the pedal feel is great and the truck stops on a dime. So, I have not had any residual valves in this truck for 6 or 7 years now and it is a daily driver. Try what you feel will give you the best result.
You can always add the valves or remove the valves depending on your braking ability. Safety first !

Great info. Can you share what bore you used on the corvette master and also the set-up you chose for power brakes? If i can do it inexpensively,I'll go power...

I wonder why the residual valves would add resistance... maybe the orface is too restrictive for the amout of fluid you have to move for bigger manual wheel cylinders?

I'll try to search for other people who have experienced residuals increasing brake effort.

Tj

This makes me wonder if i can get away with a 1" m/c for increased brake force if im using the residual valves to keep the preload on the cylinders so i dont need as much fluid....

1" bore would give me 20-25% greater force than a 1.125"...

Tj

Wow, this is a long thread...
Can you just try something see how it works at this point?