I’m trying to find a source for these so I can get my original masters rebuilt. Anyone have a source for these anymore?

I assume you are talking about non hemi disc?
People have been using the Raybestos MK551 kit to get the seals to rebuild those, kits with the correct primary piston haven’t been available for decades. However sadly that kit was discontinued recently.
I posted about this around a month ago on another forum-
https://forum.e-bodies.org/wheels-t...171-master-cylinders-discontinued/10767/
I’m not sure where if any correct seals ard available now that kit is gone. Maybe some kits are still out there at part stores somewhere, so grab any you can find.
A member here was selling kits he’d made up, maybe he still has them, I think it was NS1AAR.

If someone finds one I need it too. please post who had them

Well looks like waited too late. I talked to Brad about mine and he gave me the same bad news. He is trying to find a fix. I do have two NOS ones left. I guess I’m not completely stuck. Thanks.

Can someone post pictures of original pistons and seals. This was a 1" bore correct?

Here are NOS pistons alongside a 551 kit. You can see the primary piston assembly is shorter in the kit. That is why the seals needed to be removed and installed on the original primary piston. The 9171 has a 1" bore. The Mopar 67-70 drum brake master cylinder is 1" bore also, but sadly the seals are not the same,

What numbers on original pistons? And you meant pistons not same correct (you said seals)?

I have repo pistons and a couple of kits based off nos dart kits

The OEM primary piston assembly for a '9171 is stamped 9174, it is the gold colored piston assembly in my picture. The secondary piston which is the green one, is stamped 748.
The A body disc kit MK551, which has the shorter primary piston assembly, is also 1" bore diameter, and has the same primary and secondary seals. Therefore, people have been buying those kits, pirating the seals off the primary piston assembly, and using them to rebuild original '9171 primary pistons, or on pistons like NS1AAR and Brake and Equipment were making, to rebuild '9171s missing their pistons or with damaged pistons.
Now that the 551 kit for the A bodies is discontinued, the challenge is finding if there is a brake master rebuild kit that has the correct style seals so that these master cylinders can still be restored.
In the meantime, grab a MK551 kit if you can find one anywhere, or buy NS1AARs kit while you still can, if you have a '9171, or else you'll have to spend a long time searching the world and paying through the nose for these NOS or NORS down the line,
Bendix made master cylinders for all the automakers in the late 60s and 70s. Some other makes had 1" bores and might have used the same seals as '9171s, so the question is which ones and are there kits for them still available aftermarket that we can buy and pirate the seals off of?

Thanks Brad, Did a little research last night. It is funny some mistakes in the references. Since the 70-72 B and E have the same KH disc brake system, it is a little weird to me they used the 1" bore vice the 1.125 they had been using. I guess since they switched to a single diaphragm Bendix booster for the E body, they felt they needed to make an adjustment.

The 70 Plymouth Service manual, doesn't correctly call out the brake system. It implies the MC bore is 1 1/8. But they have the disc dia wrong, so I think they used the C body data. The 71 Service manual corrects the data, but now they are using the 1 1/32 MC.

Having looked at some of the bell cranks, it does look like a slightly different ratio for the E body versus the 70 and earlier B body. I am assuming petal ratio between a PDB B and E are the same.

A 1982 Wagner catalog called the 2229171 and their replacement a 1 and 1/8" bore. Mistake?

Bendix catalog when they were Allied calls it a 1".

Raybesto catalog has the Plymouth called a 1 1/8", but the dodge challenger 1" and 2 different parts numbers, so go figure. In all cases I am looking at the Non-hemi disc versions. Hemi's did have the 1 1/8"

No wonder so confusing in the day. These catalogs are from late 70 to early 80s versions.

So here is my thinking: those pistons look pretty close to some of the B body Bendix 1 and 1/8" types. If the MC is bad anyway and needs to be resleeved, and if (big if) the compensating port locations are the same position as the B body equivalent MC. You might be able to move up to the 11/8 bore. Use the B body piston kit which is still available, or maybe the 11/32 is same too.

Granted this will increase the pedal force needed to get the same braking effect, but it might be an acceptable solution especially if the pistons are bad, and MC out of tolerance from pitting.

You have my dimensional data from the B bodies. You might compare it to those E body pistons if you still have them.

I still think the best solution is to investigate mc kits for late 60s early 70s cars with 1” bores still on the market, buy some and check the seals to see if they were the same. If I still worked at Raybestos I could track this info down quickly, but sadly I don’t have access to that info any more.
They listed 36283 as the correct MC for disc brake ‘70 E bodies, but that was wrong as it’s the 1-1/8” bore B &C body part. But it fits and basically works. The aftermarket is concerned with fit and function, not restoration, and some of their info got crossed up over the last 50 years anyway, so using their catalog info for researching for info on what was installed on cars originally isn’t productive.
Another concern is that there is no guarantee that kits on the market today for 1-1/8” or 1-1/32 mopar master cylinders won’t get discontinued at some point also, so modifying a 9171 for a larger bore might result in a Frankenstein that can’t be rebuilt either.
There will come a time where certain features on these cars won’t realistically be restorable to day one. We already see that in some cases. For example the complex “ powermaster” master cylinder on ‘80s Buick GNs are not available anymore, nor are the parts to rebuild one available, so many of their owners are converting them to a conventional vacuum booster/master cylinder system to keep those cars on the road.

Each has to be evaluated on its own merit, but I have seen too many MC that due to retained water, have pitted and the corrosive combination has damaged the pistons, even if just at the bottom. So if you do not have a piston to go in a MC what good is it. Cast Iron does some funky stuff when it corrodes and expands. That late 70 catalog did not even list a kit for the MC. They must have dried up pretty quick. Plus an overbore does not require a sleeve which could develop issues.

Yes, the Ray catalog showed the 36283 for the Barracuda, but a 36393 for the Challenger. Sometimes Rock auto is the same way. Can't find a part listed under Plymouth, but there it is under dodge.

When they stop making 1 1/8" pistons, they will probably stop making brake parts. It way too common considering how many years and model had it. The 1" actual kit is long obsolete. I would also think getting seals would not be too hard. Plenty of place will make custom seals. So anyone off the Reproduction parts dealers could go that route.

That would be better than taking good seals off a piston an installing on another. You risk a damaged seal 2 times, vice one. I am a B body guy and have a stash of those kits for the various disc cars. Just brainstorming for the E body guys, since I have been intrigued by the subtle engineering changes to the MC and Pistons. So lately I been diving into the Drum side.

I would like to find a master cylinder rebuild kit for a 1970 U-code Cuda. It has 11 inch manual drum brakes. Can someone provide me with the Bendix or Wagner part number for that kit?

Thanks,
David

A picture to ensure you have the correct OEM would help. But that is the common Drum MC from 67 to 70. Those are still available after market like rock auto, and several on Ebay if you want Mopar OEM.

I am just a hobbyist, and studied brakes out of necessity for my B body. Stuck with it by studying in more detail the internals of MC. It surprises me that some of the current business that do this don't source there own parts considering how other hobbyist go an get parts made. Especially since in many cases they should have good technical documents from the period. I guess the focus on the modern work, overrides some of this. But it still amazes me.

All the variations of the B body 1 1/8" Bendix from the 67-70 and they only used 2 types of seals. 3 different primary pistons, 4 secondary, but the seals and configuration are the same. The generic market turned this into just two repair kits, and the actual MC are really only one. Original Bendix seals have part numbers on them.

Having said that, I spent a day on the internet and believe the MK 494 kit for Fords may have what you need. Why a brake repair facility could not figure this out? Frankly, pistons may even be closer then the 551.

If I had the actual original pistons like Brad does I could do the comparison. Plus document in detail the pistons. Similar to what I have done in the B body types.

Rockauto has 494 kits, maybe worth the cost to get one and see if that meets your needs. I would be shocked if Bendix made a new seal type/dimension for every 1" bore MC they made in the late 60s to early 70s. Especially from a Disc to Disc perspective.

I hope this helps the E body guys. Maybe the A body guys too that need the 551 kit.

Man thanks for research, dragon. I’ll order a kit and let everyone know. I’ve got some seals and a 551 kit already. Working on a couple of other deal as well. I’ve got an NOS 171 master so I can compare them.

Checked out the MK494 kit. The pushrod hole is deeper and the secondary piston stop would have to shortened. Neither of these would be a show stopper. The seals appear to be the same.

Any body know the P/N for the original MC kit or the Raybestos #

The original kit for a 2229171 is Chrysler # 3420969.
I don’t know a Raybestos number.
A company named Master Power brakes was a big player in the aftermarket back in the ‘70s. I’ve found NOS Bendix kits and master cylinders in Master Power Brakes boxes in the past.

From what I have seen, there was no Secondary Market kit for this. Maybe because of the limited production? A 77 book and no kit listed for secondary market. In fact the recent one that sold on Ebay had a 1 and 1/8" kit being sold with it.

The real question would be that Bendix should have had a kit. So if anyone had a early 70 Bendix catalog, does it list a repair kit for the master cylinder.

Can someone post a comparison side by side of the Mk494 against original piston. The secondary stop would only come in to play if the rear brakes failed with a leak, unless it is dramatically longer. How the lead seal lines up as compared to body length is what really matters. Compensation ports must remain open when pistons return to normal brake off position, and they need to be within .02" of the port. Seals must close near immediately as brakes applied. If one remains open no pressure developed until both are closed.