I bought the car with this particular master cylinder on the car. I think it is starting to get mushy. Brakes have been bled. The "nose is 3/4" long and 1 1/2" diameter. Any ideas would on what type/brand would be welcome. Chevy? Ford?

Update...There is a casting number under the item E2TA, I think It's a Ford...

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Original Post
quote:
Originally posted by Dave2811:

The E2TA casting number crosses to Dorman #M39388, which is a '83 - '85 Ford Ranger and Bronco II.

Dave its not a Ranger/Bronco master, I know because I've seen Mustang guys make that mistake. If a person buys the replacement master that the E2TA number crosses over to, you'll end up with a cast iron master designed for drum rear brakes.

My Pantera has the same master. If I had to guess, I'd bet it was purchased from Dennis Quella. I know its a Ford master, but I don't know which Ford. Its not in the SVO catalog, so it must have been a production item. I can tell you this.

There are 4 considerations in chooosing a master.

  • The oem master has a different mounting flange bolt pattern than the Ford masters (or GM masters). A mounting flange adapter is required between the master and the vacuum booster to adjust for the differences in bolt pattern.
  • The oem master had a 23mm piston, which is about 0.900". The oem/aftermarket/retrofit Ford masters come in two piston sizes, 1.000" for use with a brake booster, and 1-1/8" for use without a brake booster.
  • It appears the masters designed for 4 wheel disk brakes are a bit different than the masters designed for front disk/rear drum applications. That difference may be the check valves designed to hold back a tiny bit of pressure.
  • The last consideration, some masters have ports threaded for SAE tube fittings, others have ports threaded for metric tube fittings. 1979 through 1986 Mustangs had SAE fittings. Beginning 1987 they had metric fittings. Steve's master has brass tube fitting adapters screwed into the ports.

I used to know what application that master was originally designed for, but it slips my mind now. I believe its for a Mustang, either a GT Mustang or an SVO Mustang. One of the hi-performance versions that was equipped with rear disk brakes.

If your car is already equipped with the mounting flange adapter, then its ready for a Ford master. You'll want one with a 1.000" piston (designed for use with a booster) and designed for 4 wheel disk brakes. If you want to keep the same tube fitting arrangement, you'll need to figure out what type of adapters those are. For SAE ports, purchase a master for pre-1987 Mustangs. For metric ports, purchase a master for 1987 or later Mustangs.

You'll find a selection of brake parts at the parts houses that supply parts for rear disk brake conversions. There is a nice looking aftermarket Ford master on the market having plastic reservoirs, it kinda looks like the oem master. Wilwood also has some nice masters available. And of course, oem masters are available from Wilkinson.

-G
Many times if you can carefully remove the brass seat insert, you can remove the "pintle valve" and then put the seat back in place.....

From what I have seen, the so called valve isn't much of a valve at all....but a rubber "obstacle" for stopping LOTS of fluid flow...as if drum brakes were being pulled back into position after braking...they have springs to pull them back.....a very violent action vs the retraction of the disc pistons.

The calipers have only the retractor seals to pull them back mere thousandths of an inch, so the resulting fluid back flow is miniscule...in comparison.

I would bet a dollar that the version shown, which is normally a disc/drum M/C, still has the pintle valve bits behind the drum section (small section).

I have also heard of the hot rod guys using V6 Mustang M/C's with some success, already set up for disc/disc. I believe that they fit the older Ford boosters....but not sure about Benditalia....

Steve
Steve is correct- in the old days, we routinely tightened a sheet-metal screw into the brass press-fit flair-seats of such master cylinders to easily pull them out with pliers. Behind it was what we called a 'duckbill'-valve which could then be pulled out with needle-nose pliers. They were often found damaged so they didn't work anyway. IMHO this valve was put in drum-brake circuits of both drum-only and disc-drum combo cylinders. The keep-alive pressure in drum brakes is about 12 psi while disc brakes use a 2 psi valve, so you certainly don't want to use the wrong one! On the GM master cylinders used in Pantera conversions, the 2-lb keep-alive valve is a thick nickel-sized rubber thingy with a tiny coil spring & a ball bearing for the check-valve, installed under one of the the plastic fluid reservoir spouts.
I personally don't use such valves at all, since they cause a small amount of pad-drag as the price one pays for getting that theoretical 2-millisecond-decrease in brake response time. Our modified brakes can lock wide tires very quickly when panic-stopping, so it's not needed, and my pads & rotors live longer without it. But then, the only stock parts of our brakes left are some of the hard lines.... so YMMV.
Pantera International Magazine issue 107, Summer of 2001, has an article about brake masters authored by none other than mister Chuck Melton. He refers to the aluminum Ford master as the "SVO master". That's it. So I went through my stack of SVO catalogs and found one part number for a master in the price list in the back of the 1996 catalog, #M-2032-R58. The price list refers to this master as a 1995 Cobra master. Its not pictured or listed in the catalog itself, just in the price list.

It occurs to me that since Louie remembers buying one of these from Hall Pantera, and since Hall Pantera was a Ford SVO parts dealership ... perhaps the first thing to do is give Tara a call and ask if she still has these masters on the shelf.

rock and roll

-G
OK, I know this is an old post...buttttt, we need some clarity....

I just picked up a car with what would appear to be this same MC. Timeframe of install would be " a long time ago in a galaxie far....."! Pedal is getting mushy and front brakes may be sticking.

Dave is right, the E2TA number probably now crosses to a E3TZ-2140-B number which IS the 93-85 Ranger/Bronco II Unit.

What is good about this one? As of today, it is STILL offered by Raybestos (RockAuto.com) in ALuminum with LH side ports as shown in the original pic. Yes, you probably need to put adapters in the line, but they are for standard flares, not metric, so easy cheesy. Even metric to SAE adapters are now available....so not that big of a deal either!

15/16" bore. About $41 Raybestos MC39388

I have some stampings in the side of my unit "GC62B" with perhaps one more character....need to recheck it with a brass brush and a good lamp! But that is a long way from a E3TZ (1983 Truck line part was the original intention.) part number, unless it is on the bottom.

THE SVO MASTER CYLINDER(!): Is not a LH outlet unit. It is a 1 1/8" bore unit, in aluminum, with RH side ports. USED 1984-1986!

SVO IN 1987-1989, went to separate plastic reservoir design, and I think for a pretty good slant....angle....and still has RH ports.

So if you have an aluminum M/C that still uses the booster spacer, with RH ports you probably have the 1 1/8" unit.

There is likely a "generic" two sided ports version of this unit also, but will take the guys at the auto parts store some time to fish it out of their system!

I also found a 1990 Ranger unit, with the detachable plastic reservoir that is pretty flat, 15/16" bore, LH ports, aluminum, and std port threads in a Raybestos MC39567.

It changes in late 90 to a 1" bore but then also changes to metric bubble fittings, so you would need adapters accordingly. The angle on the reservoir also is a bit off flat... Raybestos #MC39953

WHAT I DO NOT KNOW ABOUT ANY OF THESE UNITs except for perhaps the SVO unit....is about the residual pressure provisions in the smaller reservoir fitting. Typically the larger reservoir is for the front discs..... SVO's were 4wdiscs. Rangers were front disc typically so I would suspect something behind that seat for the small reservoir. Will take my old one apart and see whus up!

Just for sh*ts and giggles, I also found a 1980 Chev Caprice unit with LH fittings that IS a 1 1/8" unit. But it is cast iron! MC36306 Raybestos. Too bad.....I'd be on it if it was AL!

I guess when you find something that works, take the time to either 1) write the part number on the M/C unit in sharpie marker...or 2) stamp the part number into the unit where it can be read whilst installed! and/or 3) keep the receipt or record of the part number in your log book! You are keeping a log book right? Every good pilot does....

More as I find it....
Steve

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Update.....

First, who was the idiot that put Allen bolts on a master cylinder....? Since I was at my "other" garage with limited tools, it took me a while to find a bit to fit.....normally not an issue, where a 9/16" headed bolt should have sufficed.....or proper studs and a nut..... If I had cause to remove this in the field....I'd still be beating it with rocks and sticks!

N.B. Hit Fastenal up for proper two sided studs.

OK, back to point....
Pulled this unit off and benched it yesterday for inspection. It is indeed the E2TA casting (number is on the bottom) with a 15/16" bore. (Dorman #MC39388)

Turns out it was absolutely clean on the inside bore area. Slight polishing where seals ride, but that is to be expected. Reservoir areas had some sediment buildup but over all, nothing pointing at this as the cause to "seemingly hanging" brakes. Could be rust on the rotors....

But, for my sanity's sake, will be next popping off the calipers to inspect.

I did find out that this unit did not have the residual pressure device/obstruction in the rear brake fitting which you would expect to find in a unit designated for front discs/rear drums. How you ask? Once I had the pistons out (there are two parts!) I simply shined a light into the bore and looked thru the output port holes! Saw nothing but light! Cool! Don't need to mess with that.....!

Cleaned things up with brake cleaner, lubed seals and bore with brake snot (Brake Assembly Lube!) and popped it back together.

Don't touch that dial! Tune in again next time!

Steve
Last edited by mangusta
Steve,

Does this mean you now own a Pantera? Had a problem with my 68 Galaxie where the brakes would not release immediately. Problem turned out to be in the booster.

Forest
Steve, that aluminum adapter plate has caused trouble in the past for some drivers. It carries an internal plastic bushing that is supposed to guide the pushrod extension for the MC. Some bushings were sized too close to the OD of the pushrod, and when things get overly-warm up there, the adapter hole closes up, the bushing pinches the pushrod and your brakes drag- or lock. I fixed Russ Britschgi's Pantera during a Gold Country run about 18 yrs ago when that happened. I reamed the bushing with (what else-)a jacknife; the locking went away & has yet to return. You're looking for a sloppy fit, not a precision one.
I have the same setup on mine. Just had the pedal go to the floor so need an overhaul.
Might try that Raybestos unit.
Thoughts?

Update

Ordered it from rock auto. We shall see
Last edited by tajon
The current unit that most closely matches, and is easy to get, is from a 1970 Mustang. Auto Zone number NM1378. It has the minimum 1" bore which is important if you don't like a pedal that travels close to the floor before the brakes grab. The Dorman/Ranger unit is a smaller bore, not much, but enough to tell a difference. I tried both.

The only other thing is that you will have to elongate the mounting holes outward about 1/8" each side to match the mounting studs.
RSS,

Odd that you would need to elongate any holes in that unit! You are running the 3/4"(?) spacer/adapter right? That should fit the Ford pattern..... Did I miss something....?

Other notes on previous posts:
My spacer pushrod WAS sticking a little bit. It didn't move freely back and forth.....SO, I applied Jack's custom machining with my handy dandy pocket knife and voila! Moves freely now!

I guess hearing about the pedal travel, the 1" bore is more attractive sounding....but for now, in order to get the car back on the road, will reinstall it....bore is clean.....brake lines connect....easy cheesy.

I would like an aluminum version however.... and I think the "generic" M/C that someone told me about will be the ticket. Ported for left brake lines.....and bolts up to the adapter. Cardone 131897 (13-1897) appears to be this unit. 84-86 SVO Mustang, 74-89 Continental w/hydroboost, 84-89 Mark VII with Hydroboost.

OK, that's it for now!
Cheers!
Steve
Should have stated. I don't have the spacer, and for my early 71 model, it didn't line up with the booster. I don't know if different boosters were used throughout the production run.
RR, there were in fact two different boosters used. The variation was in the OD of the big 'can' and inside, a slightly larger rubber vacuum diaphragm in the later one. Some pre-Ls that originally had a small booster will have trouble closing the hood on a later, larger replacement without strategic dents being needed. I think the bolt pattern on both ends of the boosters was the same, though. The vendors would know.

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