Leaking New Brake Cylinders

Rutty

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I've been chasing my tail with my brakes since I bought my '68 Newport. The hydraulics were shot when I bought it so I bought and installed all new cylinders and lines. Since then I haven't been able to get the brakes to work correctly. The master has been slowly losing fluid from the front brake reservoir but only when the brakes are used. I think the rear seal is leaking. I also just discovered today that the real cylinders are leaking. Can anyone give me a recommendation on where to find quality replacement brake cylinders? These are from O'Reilly's and I'm sure are cheap Chinese examples. I've attached a few photos. Am I on the right track?

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polara10x500

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BY NO MEANS AM I AN EXPERT BUT TAKE THAT CHINESIUM CRAP OFF AN BACK TO THE AUTOCRAP STORE IF THAY WILL EVEN TAKE IT BACK. MAYBE TRY TO REBUILD THE OLD CYC. OR FIND NOS. I'VE HAD A FAIR SHARE OF BRAKE JOBS IN MY DAY AND WITH LOTS OF PATIENT YOU'LL GET IT RIGHT. SURELY SOMEONE ON HERE CAN DIRECT YOU TOWARD SOME USA MADE CYLNDERS. I RESTORED THE BRAKES ON MY 70 /6 DUSTER ALL DRUM MANUAL AN THAY WERE THE BEST BRAKES ON AN OLD CAR I EVER HAD MIND YOU IT WAS A LIGHT CAR BUT THAY WORKED GREAT.
 

Davea Lux

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Craig@mobileparts, a vendor on this site has quality replacements. The chicom wheel cylinders suffer from a lot of quality control and machining issues, so avoid them. I actually got a set from AutoBone that had the cups installed backwards, that was when I stopped using China crap. Castings on the chicom units are also usually of poor quality. If the booster has had brake fluid leaking into it, it is living on borrowed time and should be rebuilt. From the photo, yours does not look like the Master has been leaking out the rear.

Dave
 
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mrfury68

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Like Davea Lux mentioned in a previous post, Craig @mobileparts will have the quality, name brand parts our old cars deserve. He is a member here and a guru when it comes to new replacement parts for our rides. When you leave him a message he will get back to you. His prices are reasonable for the quality parts you are buying and his service is second to none. Several of us on this site have used him for parts and are very satisfied.
 

CBODY67

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Back when the cars were "used cars", it was common practice to disassemble the wheel cyls on the car, wipe them out, flush with some brake fluid in a squeeze bulb, wipe again and inspect. Then use a wheel cyl hone on the end of a drill motor to clean them up a bit. Flush with brake fluid again, the put a "wheel cyl kit" in the reconditioned cylinder. Bleed the brakes and call it "done".

Worst case scenario in more modern times, is to send the orig wheel cyls off and get them stainless steel sleeved. Then use a quality kit to rebuild them. OTHERWISE, contact Craig @mobileparts and be done with it.

Enjoy!
CBODY67
 

Rutty

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Thanks everyone for the help. I just placed an order with Craig @mobileparts for new wheel cylinders and a master cylinder. I'm looking forward to getting my Newport back on the road soon!
 

Gerald Morris

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I scoured the web and found myself some good, NOS Mopar brake cylinders, which WILL be SOON installed on Gertrude, as the chineseum SLAG cylinders the flipper installed leave MUCH to be desired. If you train your search engine AI a bit, you CAN find the GOOD STUFF still!
 

Rutty

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Update...
I ordered all new wheel cylinders and master cylinder from Craig @ Mobile Parts. (Thanks Craig!) Got them installed, bled, and all the pads adjusted. There is a noticeable difference in how the car stops now. It's much less grabby and feels much better. It seems to stop alright but the pedal is at the end of it's travel and actually bottoms out on the stop when braking hard. I thought there might be air in the lines yet so tried pumping them while in park but it doesn't seem to make any difference. I'm planning on bleeding the brakes again when I have some free time but thought I'd see if anyone had any thoughts on what might be causing the low brake pedal.

Thanks
 

Ghostultramarine

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I had the same problem and thought my master cylinder was no good (I bled and bled and bled them!).

Turns out I needed to adjust them better ...

Give that another try.
 

CBODY67

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Where the pedal is can be related to air in the system, but that usually results in a spongy pedal (air can be compressed whereas fluid can't). Usually where the pedal is relates to the basic adjustment of the brake shoes. Normally, on a Chrysler product with power brakes, it should be "near the top", for just a bit of pedal travel before the car starts to stop.

At some auto supplies or some online tool sellers, there is an "inside-outside brake shoe caliper". You set the caliper to the actual max diameter of the surface of drum which the shoes contact first and THEN adjust the shoes to where they match the setting on the caliper, for the shoes. This will get you very close to where you need to be, in the shoe adjustment. For the automatic adjusters to work, that base adjustment needs to be "good", too.

Make sure that everything AT THE WHEEL is correct BEFORE altering any of the adjustments at the brake master cyl pushrod or otherwise, too!

Just some thoughts,
CBODY67
 

Gerald Morris

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Update...
I ordered all new wheel cylinders and master cylinder from Craig @ Mobile Parts. (Thanks Craig!) Got them installed, bled, and all the pads adjusted. There is a noticeable difference in how the car stops now. It's much less grabby and feels much better. It seems to stop alright but the pedal is at the end of it's travel and actually bottoms out on the stop when braking hard. I thought there might be air in the lines yet so tried pumping them while in park but it doesn't seem to make any difference. I'm planning on bleeding the brakes again when I have some free time but thought I'd see if anyone had any thoughts on what might be causing the low brake pedal.

Thanks

Air in the lines will certainly cause the symptoms you describe. Bleed those lines GOOD before calling it done. It's possible some of the rubber in those NOS cylinders might be bad too. Rubber ages on the shelf. I too buy NOS parts, and have wheel cylinders ready to refit my own brakes now. (Though I buy mine from eBay dealers, who I trust more than characters who refuse to use modern communication methods,) I also have fresh rubber for the new cylinders, in case one of the NOS packages has stuff too apt to crack.

If, after bleeding the lines liberally, say, with a good pint or quart of fluid run through them to flush bubbles AND contamination out of the system, you still have mushy brakes, then you should check those NOS cylinder rubbers, and pistons, to be sure they're holding. ALSO, check the release cocks on each cylinder, in case one got left a tad loose, and is leaking. Check your adjustments. I keep my all drum rides in stop-on-a-dime most of the time, and service if they get squirrely. (The '83 pickup has big discs up front tho.) Hoses and such likewise need further scrutiny.

Your brakes as described are DANGEROUS. Fix before driving again.
 
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detmatt

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Air in the lines will certainly cause the symptoms you describe. Bleed those lines GOOD before calling it done. It's possible some of the rubber in those NOS cylinders might be bad too. Rubber ages on the shelf. I too buy NOS parts, and have wheel cylinders ready to refit my own brakes now. (Though I buy mine from eBay dealers, who I trust more than characters who refuse to use modern communication methods,) I also have fresh rubber for the new cylinders, in case one of the NOS packages has stuff too apt to crack.

If, after bleeding the lines liberally, say, with a good pint or quart of fluid run through them to flush bubbles AND contamination out of the system, you still have mushy brakes, then you should check those NOS cylinder rubbers, and pistons, to be sure they're holding. ALSO, check the release cocks on each cylinder, in case one got left a tad loose, and is leaking. Check your adjustments. I keep my all drum rides in stop-on-a-dime most of the time, and service if they get squirrely. (The '83 pickup has big discs up front tho.) Hoses and such likewise need further scrutiny.

Your brakes as described are DANGEROUS. Fix before driving again.
Craigs communication methods are just fine and his NOS parts are just like anybody else’. I’d go to him before eBay every time.

And yes @Rutty , don't drive until you can stop without fail.
 

Ripinator

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Update...
I ordered all new wheel cylinders and master cylinder from Craig @ Mobile Parts. (Thanks Craig!) Got them installed, bled, and all the pads adjusted. There is a noticeable difference in how the car stops now. It's much less grabby and feels much better. It seems to stop alright but the pedal is at the end of it's travel and actually bottoms out on the stop when braking hard. I thought there might be air in the lines yet so tried pumping them while in park but it doesn't seem to make any difference. I'm planning on bleeding the brakes again when I have some free time but thought I'd see if anyone had any thoughts on what might be causing the low brake pedal.

Thanks

I think you just need to adjust the brake shoes. The shoes should just touch the drum so there is a slight drag when you rotate the wheel. There is a tool you can use to do this:

Advance Auto Parts - Down for Maintenance
 

Rutty

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Cool, thanks for the suggestions guys! I'll check the shoe adjustments first. If that's not the problem I'll try bleeding the system some more.
 

Rutty

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I finally got some time to work on this again last weekend. A work friend gave me his star adjuster tool and I used that to adjusted the brakes. They needed a lot of adjustment. This brought the brake pedal up quite a bit and the car seems to be stopping really well however I can't get the brakes to lock up. I know you stop the fastest if you keep the brakes just shy of locking up but it seems they should lock up if working properly. I've never had a car with drums all around so don't know if this is normal or not.
 
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