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Welcome to FordPinto.com, The home of the PCCA => General Help- Ask the Experts... => Topic started by: pintoguy76 on January 27, 2014, 07:48:02 AM

Title: Master cylinder interchange with other models?
Post by: pintoguy76 on January 27, 2014, 07:48:02 AM
I have a brake problem on my 74 wagon. Not 100% sure but I think its either a wheel cylinder or a master cylinder. The master cylinder is not that old, but the brakes have never been right since it was replaced anyways and i bled the crap out of  the system.  It was a reman master cylinder, a new one is not available.


I recall reading somewhere where someone used a MC from another model - a later mustang maybe? I was wondering if anyone knew of another MC that would work that might be available NEW instead of reman'd?? I'm tired of messing with reman MC's because they never seem to work right no matter how much I bench bleed them and then bleed the rest of  the brakes at the wheels (in the correct order).


Any ideas?
Title: Re: Master cylinder interchange with other models?
Post by: Pinturbo75 on January 27, 2014, 07:53:29 AM
86 to 92 ford ranger......mi ght need adapters for the actual line but it bolts up and works. i have one on my 73
Title: Re: Master cylinder interchange with other models?
Post by: pintoguy76 on January 27, 2014, 08:16:50 AM
Thanks. That one is available new. Looks like it has a plastic reservoir on it tho is that correct on yours? Any problems filling it up or anything? Did you use the pinto pedal rod or what? Your 73 power or manual brakes? Mines manual...also mines a 74... i know some stuff was different between 71-73 and 74+ models so do you know if the ranger MC would work with a 74?


Thanks for the info!
Title: Re: Master cylinder interchange with other models?
Post by: Pinturbo75 on January 27, 2014, 11:55:14 AM
mine is the metal body and lid like the pinto one, i have manual disc brakes.;
Title: Re: Master cylinder interchange with other models?
Post by: dick1172762 on January 27, 2014, 12:24:25 PM
They used the same looking master cylinder up into the mid 80's. What you MUST look at is the piston size because it should be matched with the old master cylinder. Why don't you just buy a new master cylinder like you already have? If you buy a master cylinder off a power brake car there will be no way to keep the pedal rod in the master cylinder. And as such the rod can and will fall out of the master cylinder. I have used this type of master cylinder with a J shape bolt from the fire wall to the pedal to keep the pedal from  coming to far back and allow the rod to disconnect. I still wonder why you need to change????
Title: Re: Master cylinder interchange with other models?
Post by: pintoguy76 on January 27, 2014, 01:21:16 PM
I'm having a problem with the brakes. Its leaking fluid somewhere and I think its from the master cylinder under the dash. Ether that or a wheel cylinder. I can get a rebuilt master cylinder... which i have done on this one before and the other pintos ive had... and only one has worked right ever. Cant get an all-new one for a pinto anymore and that is what I want. That way I know the bore isnt worn out and leaking fluid past the seals and such.
Title: Re: Master cylinder interchange with other models?
Post by: tbucketjack on January 27, 2014, 04:28:53 PM
Rock Auto should have new M/C for your pinto,
Title: Re: Master cylinder interchange with other models?
Post by: amc49 on January 27, 2014, 10:56:17 PM
As Dick says the most important thing to match is exact same piston diameter. Plastic reservoirs can zoop when you have to pull and re-use them, they commonly break when the rubber seal gets hard and you try to disassemble them. The same guys who rebuild the used ones build the new ones as well and abysmal as far as quality. It got at the parts store where fully 50% of them new or used would not work right. Good ol' Chinese labor to the rescue.

If you put in one that totally looks different then make absolutely sure it comes all the way back to relieve at the small compensation port or as soon as brakes get hot they will begin to stick on and drag. You should always check the power booster rod setting as well if running power brakes. I look for like .030" max clearance there.

Every once in a while it's helpful to disassemble proportioning valve to clean it out and make sure not stuck.
Title: Re: Master cylinder interchange with other models?
Post by: pintoguy76 on January 28, 2014, 01:04:07 PM
I didnt know the proportioning valve could be taken apart and cleaned. Are there any seals in it that need to be replaced or anything?


Not sure what to do about the MC issue. Ugh.
Title: Re: Master cylinder interchange with other models?
Post by: amc49 on January 28, 2014, 07:15:36 PM
One of the immutable laws of the universe taught to me once.......... ............th ere is no such thing as something that can be put together that cannot be taken apart.

Your devotion to the task is the only limit. Now complicated by manufacturers who hate people like me and now glue or mold assemblies together now to stop us from getting into them. In most cases that doesn't even work. I fix $200 door latch assemblies on my Focus cars by grinding off rivets and drilling and tapping for screws, total cost to fix around $5 to me. No way I'm paying for expensive throwaway parts twice that I can repair myself.

Yes, there must be seals and if bad you will be presented with how to change them, luck with that and part of the task if it goes there. You can't be afraid of things if you really want to fix them. I personally have found that I can still reuse them, just like pulling a 20 year old master cylinder apart and rehoning and putting back together to work fine for another 20 (done to my Pinto wagon). The seals will still be good or............ .........they won't. Either you damage them taking apart (your fault, no insult intended) or they were bad already and part then no good till you fix it anyway. Lots of places to find o-rings, the issue becomes getting the proper thickness, size not a problem. You can often squeeze a slightly thicker one in there and it will work fine, sometimes not.

Here's a tip that may save someone a bundle on old parts. Not saying to do this at all on brake parts BUT you CAN clean parts off in petroleum distillates just like every tech or teaching method in the universe says you CANNOT on brake parts. Occasionally there may be a need to go there, I've often found that alcohol or brake fluid doesn't clean parts for squat, they don't cut the old brake fluid. I've used say gasoline, the parts will swell all out of shape and you're firmly convinced you ruined them. Let the parts sit for 2-4 days so the VOC of the fuel can evaporate from the rubber and come back to find the part is normal size and shape and good to go again. But clean now. I have already put my life on the line several times doing this through the years and I assure you the parts are OK and will work well. BTDT. They must of course start off tio begin with as still supple rubber, they cannot be hard or have cracks in them.

So, if you did solvent not knowing, then no need for panic there.

But then, I've recovered new brake pads that one week old blew a caliper seal on and fluid soaked into pads, I reused them to full length of time (years) and they stopped car on a dime.

It behooves one to be a bit cynical of all the things conventional wisdom holds for us, much of it is highly inaccurate.
Title: Re: Master cylinder interchange with other models?
Post by: pintoguy76 on February 09, 2014, 09:41:43 PM
I will check on the proportioning valve. I think I am headed for a new 86 ranger MC tho, with the plastic reservoir. Will need some adapters on the lines but thats no biggie I dont think. I'll compare the pedal travel and all that too to make sure its the same. Really want to get this things brakes working properly.....
Title: Re: Master cylinder interchange with other models?
Post by: dick1172762 on February 09, 2014, 11:06:10 PM
Unless you have power brakes, you will need an 86 Ranger master cylinder for non power brakes (O'Really's) Dorman #mc39568.  One hole will need an adapter to make the brake line hole smaller. No big deal as all the stores have them. Much better part and up to date. Just make sure its the same piston size as what is on the car now 15/16". You'll not believe how much better it'll look.
Title: Re: Master cylinder interchange with other models?
Post by: pintoguy76 on February 10, 2014, 10:28:53 AM
Yep, i knew itd need to be for a ranger with manual brakes. Still probably have to use the pinto push rod tho. And yes it will look much better and be much more up to date. Thats the idea, i just feel like the old pinto master cylinders are all worn out. Theres probably only so many times they can be rebuilt before they just dont work right anymore. And brand-new would eliminate that issue....
Title: Re: Master cylinder interchange with other models?
Post by: amc49 on February 10, 2014, 04:39:44 PM
You can only hone so much before seal pinching occurs and master then is junk.