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What type of Master Cylinder is this?


kevinscar
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Hi,

New to this forum and looking to get more involved as I learn.

I recently took possession of my Father's 1935 chevy hot rod, in order to complete it's restoration/build. It is about 80% complete and I have most of the winter to work on this project. I have a checklist of things I need to do, and one the first things is to understand why the brakes are so soft. I was just going to pop the top off the master cylinder and take a look but bumped into this. Never saw one like this before but I have to assume it's an 1935ish master cylinder. Hoped someone on the forum could help me.

What kind of cylinder is this?

Does it take normal hydraulic brake fluid?

Is there a replacement part for this if I determine it is bad?

Thank you!

post-80227-143138712789_thumb.jpg

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A bit more information. This hot rod has a el-camino back end (1964) and a mustang front end. The brakes, I have to assume are modern... it's just that the master cylinder surprised me. I did pull off the cover and it's got no fluid in there. Certainly doesn't seem right.

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Looks like a 1950s or 60s vintage master cylinder to me. Different, however from the one I recall on either my family's 63 Plymouth or the 63 Dodge truck I once had so I'm guessing it is not a Mopar unit.

Wouldn't be too surprised if that came off of the vehicle that donated either the front or rear ends.

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I would bet you are right. I guess the question is why not replace it with a more modern master cylinder. I'm not sure why they did it that way. Cut costs? I'll try to see if I can get it to work and if not, I will probably be pulling it. Thanks

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Thank you for the information. I have yet to take it into the shop and give it a good once over (my son has occupied the shop with his jeep and I'm not getting the 35 within 10 feet of his mud slinger

;) )

My thought is to try and just bleed the brakes and get fluid back in the lines and see how they perform. If they are still soft and I have no leaks, I guess I have to assume it's a bad master cylinder and I'll see if I can find one at our local salvage yard.

Just out of curiousity, do any of you think it would be wise to go to a dual brake line system if I have to change the master cylinder anyway? I realize I will have to run new brake lines, but that's not that big of a deal.

Thanks!

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Just out of curiousity, do any of you think it would be wise to go to a dual brake line system if I have to change the master cylinder anyway? I realize I will have to run new brake lines, but that's not that big of a deal.

Thanks!

As it is a modified car it would seem to me that changing out the master cylinder would not be a big deal for authenticity. And putting a dual master on will increase the safety of the braking system. So if I were you, I would strongly consider putting a later dual master on the car.

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Okay, last night my son and I bled the brakes and we were able to get some decent action. Enough I could take the car out today. I took it to a local show about 13 miles away. Once I got there, I opened the hood and found the master cylinder leaking between the vacuum assist and the bowl. I got a mirror out and took a look for the number under the master cylinder. It appears to be P48222E. I've included a couple of pictures for those of you who know this stuff. BTW, the number on the bottom of the master cylinder is seen through a mirror.

My question is, do you think the cylinder needs to be replace? I'm thinking yes but need to do a bit more research on why the leak is where it's at. I suspect there's probably some gasket in there or something.

post-80227-143138721821_thumb.jpg

post-80227-143138722221_thumb.jpg

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a rebuild kit is in order, you've got brake fluid getting past the the master cylinder piston cup and the rear seal where the pushrod goes thru to move the piston. i suspect that seal has to be leaking due to the fluid pressure you create when stepping on the pedal. charles coker, 1953 pontiac tech advisor.

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You are right, I read it backwards (I knew it was a mirror ;)).

The 222 in the number is very clear, the rest of it is pretty murky. I tried to take several pictures, the one above was the best of the bunch. I'm going to try and pull it this next weekend and I should be able to get a real good look at it then. Will post it up here.

Thanks!

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Marv had it right. I purchased a replacement MC from NAPA and put it in and it works great. I decided not to run a dual line system at this point, too many other things going on. Here's a picture of the new MC in the hot rod. Drove about 30 miles last night and don't see a single drip. Will be checking it closely over the next few days. Thanks for the advice!

post-80227-143138736936_thumb.jpg

Edited by kevinscar
pic didn't upload (see edit history)
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