Brake/ master cylinder question.. (Yes, another one)

[Xp29h]

Hi everyone! I'm kind of at my end with this brake issue.. I have researched, looked in fsm's, asked several people and don't seem to get a good answer as there aren't many people around here into mopars?? So, why not ask here where the mopar guys are!

Info - 1969 Charger 383h previous owner installed
Wilwood disc all way around with mp brake kit bm1306
I changed the cam to a more Mild cam but little vacuum. Last check about 11 inches (but haven't checked since put new msd ignition and tm6 intake on. Just had first road check Sunday. But it was short as brakes sucked!!

Master cylinder leaking where connects to booster. Brakes have been issue from day 1 as po stated that due to the cam, vacuum was low so brakes didn't work. He had an electric vacuum pump on it which still didn't make things any better. I removed it and actually brakes were same, which got me thinking the issue wasn't all vacuum. That was when I noticed the MC leaking. Obviously, the system is not original so the FSM doesn't really help me much. I have been told to go manual brakes and do away with the booster all together. I have been told just replace the MC.. I have seen many people recommend many types of MC's some work some don't. I do understand that a lot depends on the rest of the setup too!
The car is not original, nor will I be trying to get it there so

I guess my question(s) would be:
Stick with booster and replace just MC
Or go manual?

Which darn MC would be the best to go with? I don't really want to drop a lot of moola trying to find one..

Thanks for a place to go and ask for help!

 

[resq302]

Its hard to say which one would be the best. Possibly call up Willwood and see what they recommend for the kit you have? I've learned to not deviate from the factory set up for such cases as this. Especially if you buy a car with someone elses work, unless you have the paperwork to go with the car, you are always guessing what needs to be done.

 

[Xp29h]

I have found the same thing. I've been guessing from day 1 and I have a lot of the receipts! The work was not done right I believe. I have spoken to Wilwood and mp brakes. Wilwood gave me options but didn't help out much in the power or go back to manual route.. Of course they wouldn't and or couldn't either.

Thanks!

 

[JamieZ]

If the master is leaking fluid, it's probably best to find out why. If fluid can get out, air can get in, which will make your brakes unsafe.

If you can find out what master you have, I would look for a rebuild kit for it, typically they are much cheaper than a new master. Once you get the leaks fixed and the system bled, then see how the brakes work. Don't forget to bench bleed the master after the rebuild.

Personally I hate the feel of manual brakes, I'm in the process of upgrading my charger's brakes to a power set up.

 

[resq302]

Is there any way you can take a pic or find some casting numbers on the master cylinder you have on there now? A search for the casting number can usually tell you what it is from or what it will fit which should allow you to either find a rebuilt one or a rebuild kit for it.

 

[Xp29h]

I will look for the casting numbers tonight when I get home! Ill post something up later tonight!! Thanks for all the help!

 

[69Bee]

Personally, I would scrap the wildwood setup, and get rid of it on Ebay/Craigslist. I would then put the original 10"x2.5" rear brakes back on. I would then get a complete disc brake setup (proportioning valve, steel lines, steering knuckles, caliper adapters, calipers, and rotors from a 71 to 75/76 A body or B body.

The big thing to look out for is possibly having to switch the steering knuckles side to side to switch the position of the caliper. You can have interference issues with the shock. It will work fine this way; I did the same to my 69 SuperBee. The master would come from the same year of cars, and the main thing is that it needs to obviously have the same bolt pattern as the booster (2 or 4).

As far as the leaking master, forget rebuilding it, just get a rebuilt one from the parts store. If it leaks, you can warranty it, whereas if your rebuild leaks, too bad-so sad.

There will be 2 size of rotors, one about 10.75" and the other over 11". I can't remember the exact sizes anymore. If you are running 14" wheels, you need the smaller rotor, and if you are running 15" wheels, you can use either.

Good luck.

 

[JamieZ]

This is a pretty detailed article on the disc swap using stock parts:

http://www.moparaction.com/tech/archive/disc-main.html

DrDiff also sells kits that provide all the parts as new/reman

 

[clemul]

If you are doing the mopar 73-75 dart disc spindle conversion using the stock spindles and proportioning valve and 78 cordoba 11.75 rotor adapters ,NAPA has nice steel piston rear mount, bleeder valve on top, black anti rust coated rebuilt chrysler calipers for the 80 diplomat in their total eclipse line.

 

[Xp29h]

Update: no casting numbers located. Maybe on the underside?? Can't see or feel any? I've added a pic of the booster and mc. It's a little old as I've cleaned things up a bit under the hood.

I emailed MP Brakes re: a rebuild kit. This is the 3rd time I've emailed and no response so I'm not holding my breath on this one either.

I did contact wilwood again, got a different guy who pointed me in the direction of one of their MC's (of course) part # 260-133-75. That would be going back to manual without the booster and keeping their brakes on for now. I would also need an adapter plate. This would give me time to do some more research and see if I could try to find the right parts as mentioned above.

The rag underneath is stopping the brake fluid from dripping all over!

- - - Updated - - -

Update: no casting numbers located. Maybe on the underside?? Can't see or feel any? I've added a pic of the booster and mc. It's a little old as I've cleaned things up a bit under the hood.

I emailed MP Brakes re: a rebuild kit. This is the 3rd time I've emailed and no response so I'm not holding my breath on this one either.

I did contact wilwood again, got a different guy who pointed me in the direction of one of their MC's (of course) part # 260-133-75. That would be going back to manual without the booster and keeping their brakes on for now. I would also need an adapter plate. This would give me time to do some more research and see if I could try to find the right parts as mentioned above.

The rag underneath is stopping the brake fluid from dripping all over!

 

[resq302]

kind of looks like the master cylinder on my charger which is a disc / drum brake factory bendix set up. Here is a reman'd one done by A1Cardone (not a big fan of their rebuilds though)

A-1 CARDONE Part # 101475 Reman. w/ Reservoir
Front Disc Brakes; Rear Drum Brakes

 

[themechanic]

Where does that extra line tapping into your booster vacuum go?

Go to Pirate Jacks and order the new Bendix booster and master combo and forget it. Stock always works. It should do fine with your existing discs.

 

[Propwash]

Where does that extra line tapping into your booster vacuum go?

Go to Pirate Jacks and order the new Bendix booster and master combo and forget it. Stock always works. It should do fine with your existing discs.

Guessing something to do with his headlight door actuator's, being a '69 charger.

So what do you mean when you say "The brakes don't work"? As in they're hard as a rock and take crazy pressure to stop or the pedal goes to the floor? A decent electric vaccum pump would have definitely resolved any low vacuum issue for your booster, if installed correctly and working properly. As far as manual brakes vs. power, the power brakes take the cake when it comes to pedal effort and "right now" stopping. Manual brakes, vacuum is obviously not a factor. I agree with themechanic...Ditch that leaky master and GM Style booster/linkage and replace with an actual factory style Bendix system. Also, does the car have a proportioning valve in it or just a distribution block (drum brake car)?

Here's the kit themechanic speaks of:

http://www.piratejack.net/index.php?page=shop.product_details&flypage=yagendoo_flypage_1.tpl&product_id=400&category_id=49&option=com_virtuemart&Itemid=6

 

[Xp29h]

Thanks! It's about 1 am here and the dog had to go out! That will ness up a night sleep!!

Yeah, brakes don't work! I have to stand on them, pedal right to the floor. Barely anything. Before the MC really started leaking I would notice a little breaking power for the first push of the pedal but then quickly gone. That was why I figured there was another issue besides vacuum.

As far as extra line, right on with the headlight actuators. Vacuum runs those doors. That's been cleaned up a little since the picture was taken.

The car had a vacuum pump on it originally when I bought it. It checked it and it was sending 25 in. of vacuum but the brakes didn't work really and different at that point. The switch to the pump wasn't installed that great so I unhooked it and tried the brakes just to see and it didn't make a bit of difference. It was hooked up correctly and the system is hooked right now. I just think the MC is bad causing leaking and air, which we know isn't going to work. The car car does have an adjustable proportioning valve and disc all the way around.

I'll take a look at pirate jacks when I get back up later this am. Dog is in.. thanks!

 

[Propwash]

That's a lot of vacuum @ 25HG! I run a CVR Electric vacuum pump and typically my HG is 15-18. Car stops great. Anyways, brakes are sinking all the way to the floor..Tell tale sign of air in the brakes and/or a failed master. Another thing was when you initially got the car (and before the leak), you would have a bit of initial braking but quickly gone. Is that saying you would hit the brake once and it braked fine, but then a second pump and it would fade? Or is that saying for the first part of the pedal travel it braked well, but the further you pushed down on the pedal, the brakes would fade? Troubleshooting between the two scenario's would definitely point to two different issues, so that's why I ask.

As far as a hard pedal....Couple things will do that. The real apparent, a failing/failed Power booster or insufficient vacuum for the booster. Another would be a large bore master cylinder. From the looks of it, I would guess that's the typical 1 1/8" bore master seen with a lot of aftermarket kits. If so, I can't imagine that would be a culprit for a hard pedal with your set up, but that's just a guess. Power brakes, typically you want a bigger bore vs. manual.

Going off all that, i'd say the leaking master is causing your foot to the floor issue, but i'd say you have a combination of issues. The other would be hard pedal without results. I'd point that at the booster. If you have/had 25HG, your brakes would bring that Dodge to a screeching halt pronto, if all was working well. It's really too bad MP Brakes won't get back with you, but I can imagine that's no big surprise. They sell a ton of those kits across all makes/models. If I was in your shoes, i'd be pretty frustrated. Nice '69 Charger to drive around, but the brakes make it a death trap, so it sits.....Brake fluid leaking all over, stripping paint...no support from MP Brakes after multiple attempts, and Wilwood just tries to pitch more of their product, forcing a conversion over to manual. My 2 cents....Like mentioned, I'd dump that GM style booster and leaky master in the garbage can where it belongs and go with a bendix set up. I wouldn't waste my time or money converting to manual, power brakes are better, no arguing that. I'd vacuum tune the engine to see if I could grab just a couple more HG's. You're real close at 11, just a couple more and you could run a canister or even nothing at all. If that isn't possible, you always have that electric vacuum pump. Myself i'd either incorporate a vacuum pressure switch into it so it kicks in/out automatically or just go aftermarket with CVR, SSBC or others. I'd go over the entire rest of the system, looking for pinched or kinked metal lines, worn/cracked/collapsing rubber lines, leaky bleeders, condition of the pads and overall health of the brakes at the wheels. After that...I'm pretty positive my Fred Flintstone braking days were over.

Good luck

 

[resq302]

I have to say, the stock Bendix disc brake system I have in my charger from the factory is awesome. The only issue they seemed to have is the common 4 piston leaking which you can get away from by having them sleeved with stainless. Either way, the dual diaphragm Bendix booster with master cyl would probably be a huge improvement for you.

I also agree that most likely your problem is the bad master cylinder. What Propwash explained is a typical bad master cylinder. Pedal goes all the way to the floor usually means it is bypassing internally which is why you are getting the leaks. Quite possibly due to moisture in the bore causing rust from lack of use.

 

[Xp29h]

Thanks for all your posts. I knew they would be right on track with good ideas! Going to tear the MC off this weekend. I'll keep you posted on the progress. Again, thanks!!

Before I do that I'm going to vacuum tune and time it up tomorrow night and we will see just what we have.

 

[old_skool]

A lot of times when the master leaks at the booster, the booster slowly fills with brake fluid, pop off the large vacuum to the booster and run a small vacuum hose into it towards the bottom, pull it out and see if its soaked with brake fluid, if so, going to have to remove it and clean it out if you keep the booster, like most have suggested, dump that system for something more reliable and easily replaced/repaired from your local parts stores.

 

[Xp29h]

Yeah I figured that the MC had been leaking for a bit but I didn't have any signs. So I figured checking the booster for fluid. Good call though old_skool!

Ill let you all know what I find when I get it apart! Besides the obvious now......JUNK!!

 

[Xp29h]

Sorry for taking so long but H.S. baseball season is in playoff time..so I haven't had much time to get back to it..but here is where I am..

- The booster was dry of fluid, that's good.
- I got the exhaust buttoned up tight and it made a huge difference. The drivers exhaust manifold wasn't flat so leaking by.
- once running good, vacuum test shows 10 inches with cam..
- with that I decided to try a manual brake setup

Question... Will the linkage for the booster and push rod work or do I need something different? I will try to get a pic or two up here soon of what is there now..