'67 Monaco master brake cylinder questions

[MoPar~Man]

An observation I see on rockauto and any local parts supplier is that the base engine for the '67 Monaco is a 383 but my car (bought new by my dad) came with 318 polysphere (which I replaced later to an LA). Now, the engine shouldn't matter when it comes to the master brake cylinder- right?

But here's the conundrum: If you look up a '67 Monaco with 383 vs '67 Polara with 318, they point to different master cylinder part numbers. Does that mean they had different brake boosters?

My current (not sure if it's original) master cylinder is leaking, the rear reserviour was dry (for the front wheels). I filled it and tried to bleed the front brakes - but nothing comes out when I back off the bleed screws. Bleeding the rears works fine, and the rear drums do grab when brake is pressed (but pedal goes down quite far).

I could rattle off the Cardone / Dorman / centric part numbers I see and the parts people are seeing, but I can get locally a master cylinder for a '67 Monaco with 383 but not '67 Polara with 318 (that one I'd have to get from rockauto).

So, any help or guidance here is welcome.

 

[57fury440]

I would replace it with the same type that is in it now. Take it off and see if your local parts store can match it. Make sure that your lines are not clogged and check the wheel cylinders as well.

 

[volksworld]

the contents of the resevoir went somewhere...probably into the booster...

 

[Loadrunner]

Try to rebuild your original, if you can find a kit, and if you can't I've been known to buy a reman unit for $30 something and rob the parts out of it because I liked my original casting better.

 

[MoPar~Man]

Ok, I just checked rockauto and rock shows the exact same list of master cylinders for '67 monaco with 383 and '67 polara with 383 and 318.

The master cylinder I can get locally is a "blue streak" 36221 (Napa). If I do a web-search that it appears that it might be the same as a Raybestos MC36221 which is shown as not compatible with '67 Polara (any engine) but IS compatible with '67 Monaco (383 and 440).

 

[Loadrunner]

I ended up w 2 cases of 1968-69 Wagner dual master cylinders a while back. I should peddle a few but too much of a hoarder.

 

[MoPar~Man]

The car had been sitting for 20 years in storage, it might have lost most of the rear reservoir before I put it in storage. I filled the rear reserviour but the level doesn't drop when I open the front brake bleed screws. There is brake fluid weeping out of a hole on the lower mounting face of the master cylinder.

Some of these P/N application differences might be to account for (a) front disk brakes and (b) manual vs power brakes.

Was power brakes or disk brakes optional for '67 Polara / Monaco?

Odd. I see indications that the Raybestos MC36221 is compatible with Monaco years 67-70 but for Polara only 1970.

 

[Loadrunner]

They usually leak out the back when failing. Unless the bore is excessively pitted, you run the appropriate hone on a drill back and a forth a few times, wash and dry, install new parts and back on the car.

I personally like gravity bleeding the brakes but give it time.

Brake fluid is hygroscopic - absorbs water from air - and should be changed every few years but how many car owners actually do it?

 

[TxDon]

If your car has been sitting unused in storage for 20 years you need to do a complete brake system inspection and overhaul replacing all cylinders and hoses plus checking all lines and connections for rust and leaks. All the linings and drums also need checking plus front and rear wheel bearings should be inspected and repacked. You may also need to rebuild the brake booster. Sorry to be blunt but long storage can be very destructive especially if it was in a location subject to humidity. I have been through this many times and you cannot take shortcuts when it come to the brakes.

 

[1970FuryConv]

I also agree with rebuilding what you have. 20 years in storage probably dry rotted the rubber seals in the master cylinder.

 

[MoPar~Man]

I bought the Napa 36221 master cylinder. It came with a small rubber bellows shield just like what I see on-line for the Raybestos MC36221 and even the yellow plastic port inserts. For what it's worth, this is marked on the box in several places as a "new" MBC, not rebuilt. Here it is compared with what I had on the car:

The dimensions of the chambers are slightly different. It came with a small rubber bellows, which I'm not sure if I'm supposed to use somewhere. There isin't one around the rod coming out of the vacuum booster. While removing the front line from the MBC it broke at the fitting, so I also cut it on the other end at the distribution block. Here is what the 2 ends look like (and the bellows):

I don't think I'm going to find a pre-made length of brake line with 2 different size fittings on it, so I guess I'll have to buy one and cut one end off and put a different one on there?

 

[TxDon]

That is the MC I used on my 66 conversion, the rubber bellows is not needed if you have the Midland Ross booster. You can buy the correct MC flare nuts at Fedhill along with cunifer tubing and other fittings for new lines.

Federal Hill Trading Company

 

[Loadrunner]

The short boot goes on the back of the MC for manual brakes applications.

On every single old Mopar rig I own I often or continually spray the flare fittings at the MC so they will come loose when needed. If the line starts to turn with the fitting, stop, spray, wait, turn the fitting back and forth until it lets go of the line.


In extreme cases the flare fittings might be hopelessly frozen to the lines, but for everyday drivers with regular spraying as preventative maintenance, removing the lines should be fairly painless.

Bench bleeding.

I don't do it, prob should, if you have the fittings and instructions, do it, but in most cases the new MC's fill just fine, and I leave the lines slightly loose at the MC for air bubbles to work themselves out, when bubbles cease, lock the fittings down and you're good.

Purging the whole system - as recommended - at proper intervals is greatly aided by a brake system power bleeder such as this one.

Branick G300A Brake Bleeder (No Adaptors)

I scored mine at a yard sale. Guy having the yard sale says "if you know what it is you can have it" and I had the right answer.

 

[1970FuryConv]

I bought the Napa 36221 master cylinder. It came with a small rubber bellows shield just like what I see on-line for the Raybestos MC36221 and even the yellow plastic port inserts. For what it's worth, this is marked on the box in several places as a "new" MBC, not rebuilt. Here it is compared with what I had on the car:


View attachment 559647


View attachment 559649


The dimensions of the chambers are slightly different. It came with a small rubber bellows, which I'm not sure if I'm supposed to use somewhere. There isin't one around the rod coming out of the vacuum booster. While removing the front line from the MBC it broke at the fitting, so I also cut it on the other end at the distribution block. Here is what the 2 ends look like (and the bellows):

View attachment 559650

I don't think I'm going to find a pre-made length of brake line with 2 different size fittings on it, so I guess I'll have to buy one and cut one end off and put a different one on there?

Those fittings can be cleaned up on a wire wheel.
If you use Nickel-copper line like TxDon and a bending tool and a flaring tool, I think you will be fine making your own line.

 

[Big_John]

I bought one of these and it works well. Not for a pro, but great for a home shop.

Amazon product ASIN B00CJ5DY16
Money well spent for me as I was having an issue with a bad wheel cylinder, but honestly, a vacuum pump can also do the job, just not as efficiently and be used for other things.

Amazon product ASIN B00265M9SS

 

[MoPar~Man]

As was suggested, I'm going to re-use one of the fittings (the larger one that screws into the MBC). Can someone tell me why they used different thread size on the same line? I have some pre-made sections of brake line, with same fitting on both ends, either one will fit on the distribution block (and they are longer than the dinky original fitting that was hard to reach with a wrench).

I have a flaring tool that I bought maybe 10 years ago from Princess Auto, I might have never really used it until now. I tried to create a double-flare with it - the pin of the insert piece didn't fit inside the brake line. I had to file it down so it fit. I tried making a few test flares. Step 1 is to use the insert piece to create a flare, then step 2 is take the insert out and press again directly with the screw tool. But all I ever get after step 2 is a bigger single-flare. It's not doubling or folding over to create the double flare. I'm going to have to look around and see if I can find a decent flaring tool that doesn't cost a fortune.

Edit: So I was assuming that because the insert die with the smallest pin was not the correct one to use for 3/16 brake line, I was using the next size up, which the pin didn't quite fit hence I filed it to fit. I've since tried to make a few flares with the die with the smallest pin, which is a very loose fit in the tube, and it might be working better, but the final press with just the screw doesn't really give a nice result, usually the flare is off-center, not symetrical, and the surface is torn up (not smooth). Do I have to use a brake line made from a different material to make this work?

I found a photo on-line that looks exactly like what I've got:

Summit racing has an On-Car flaring tool, I wonder if that's a generic design that I can buy locally...

The brake line material I'm working with has an external appearance of aluminum, is very hard to bend by hand, and after flaring when I look down inside the flare I can see hints of what looks like copper? They say that copper-nickel material is the way to go, but maybe that's not what I have?

 

[Loadrunner]

Flaring takes some practice. Learned it in school. Double flaring separates the men from the boys...

 

[TxDon]

As was suggested, I'm going to re-use one of the fittings (the larger one that screws into the MBC). Can someone tell me why they used different thread size on the same line? I have some pre-made sections of brake line, with same fitting on both ends, either one will fit on the distribution block (and they are longer than the dinky original fitting that was hard to reach with a wrench).

I have a flaring tool that I bought maybe 10 years ago from Princess Auto, I might have never really used it until now. I tried to create a double-flare with it - the pin of the insert piece didn't fit inside the brake line. I had to file it down so it fit. I tried making a few test flares. Step 1 is to use the insert piece to create a flare, then step 2 is take the insert out and press again directly with the screw tool. But all I ever get after step 2 is a bigger single-flare. It's not doubling or folding over to create the double flare. I'm going to have to look around and see if I can find a decent flaring tool that doesn't cost a fortune.

Edit: So I was assuming that because the insert die with the smallest pin was not the correct one to use for 3/16 brake line, I was using the next size up, which the pin didn't quite fit hence I filed it to fit. I've since tried to make a few flares with the die with the smallest pin, which is a very loose fit in the tube, and it might be working better, but the final press with just the screw doesn't really give a nice result, usually the flare is off-center, not symetrical, and the surface is torn up (not smooth). Do I have to use a brake line made from a different material to make this work?

I found a photo on-line that looks exactly like what I've got:

View attachment 559727

Summit racing has an On-Car flaring tool, I wonder if that's a generic design that I can buy locally...

The brake line material I'm working with has an external appearance of aluminum, is very hard to bend by hand, and after flaring when I look down inside the flare I can see hints of what looks like copper? They say that copper-nickel material is the way to go, but maybe that's not what I have?

I just finished doing all this and more brake work on my 66. Lessons learned the hard way - 1. buy all new parts and fittings, cheap insurance against leaks. 2. Buy or borrow a good professional flaring tool, I had the same problems you did and the flares leaked. 3. If the tubing you have is hard to bend it is not Cunifer. Another needed tool is a tubing bender for any fairly tight bend.

 

[MoPar~Man]

Yea well I'm sure that $500 worth of flaring tools helps. I went out and bought some of that copper-nickel brake line. It is way more flexible than steel, but seems just as hard to cut with a hacksaw. It is easier to flare with my dime-store flaring tool, but not a lot easier. Satisfactory double flare.

 

[1970FuryConv]

As was suggested, I'm going to re-use one of the fittings (the larger one that screws into the MBC). Can someone tell me why they used different thread size on the same line? I have some pre-made sections of brake line, with same fitting on both ends, either one will fit on the distribution block (and they are longer than the dinky original fitting that was hard to reach with a wrench).

I have a flaring tool that I bought maybe 10 years ago from Princess Auto, I might have never really used it until now. I tried to create a double-flare with it - the pin of the insert piece didn't fit inside the brake line. I had to file it down so it fit. I tried making a few test flares. Step 1 is to use the insert piece to create a flare, then step 2 is take the insert out and press again directly with the screw tool. But all I ever get after step 2 is a bigger single-flare. It's not doubling or folding over to create the double flare. I'm going to have to look around and see if I can find a decent flaring tool that doesn't cost a fortune.

Edit: So I was assuming that because the insert die with the smallest pin was not the correct one to use for 3/16 brake line, I was using the next size up, which the pin didn't quite fit hence I filed it to fit. I've since tried to make a few flares with the die with the smallest pin, which is a very loose fit in the tube, and it might be working better, but the final press with just the screw doesn't really give a nice result, usually the flare is off-center, not symetrical, and the surface is torn up (not smooth). Do I have to use a brake line made from a different material to make this work?

I found a photo on-line that looks exactly like what I've got:

View attachment 559727

Summit racing has an On-Car flaring tool, I wonder if that's a generic design that I can buy locally...

The brake line material I'm working with has an external appearance of aluminum, is very hard to bend by hand, and after flaring when I look down inside the flare I can see hints of what looks like copper? They say that copper-nickel material is the way to go, but maybe that's not what I have?

With my Old Forge flaring kit, which looks exactly like yours, the size is marked on each insert. Not true of yours?

The first press of the insert into the line should give a bubble shape on the line. Removing the insert and doing the second press collapses the bubble and gives the completed double flare.