I love my truck but there is never a dull momment! As I was undernieth attaching nuts/washers to the bed bolts, I noticed seeping from the bottom of the rubber boot that the push rod goes through on my master cylinder. Although the level in the reservoir is still good nevertheless I need to resolve this. I see there are rebuild kits out there for around $30 but I am thinking that I may be better off replacing with a new master cylinder that I can get at NAPA. Since I have never removed/replaced one, is the job fairly simple? It looks pretty tight to manuever a wrench in that area. Thanks. Steve

 

Seals going bad from age and wear is typical cause of this. I recently replaced the MC on a car that started seeping out the push rod boot about 6 months before the leak got to the point of a good squirt each brake application. So you have a little time to replace or repair the MC. How old is the MC? If it is more than 25 years you might have some rust and pitting helping cause the leak. For that reason on old ones I usually go with new or rebuilt by a reputable outfit. It can be frustrating to take the MC out, disassemble it for cleaning and rebuild, and find rust and pitting in the bore.

 

Any leaking of fluid in the braking system is serious and needs to be addressed asap. It's even more critical in older vehicles with a single circuit hydraulic system. One small leak can and will lead to total and catastrophic brake failure.

Replacing the master cylinder is a simple, bolt-on procedure. Using a new master rather than trying to rebuild an old one is a good idea. As mentioned above, you might find it a bit frustrating if the cylindcer bore isn't perfect. Be sure to bleed the new m/c before installation, then bleed and flush the fluid in the rest of the entire system. You'll be glad you did.

 

Since you said it was coming from the rod boot. I am wondering if you have a rod that is the correct size for the master cylinder. If it is to small it can cause a leak. If the rod is not adjusted correctly repeatly bottoming out of the rod can cause the leak. chuck

 

Thanks guys. I will be picking up a new one at NAPA and installing this weekend.

 

I just went thru the fun of rebuilding my MC on my '53 F250. Once i figgured out how it came out it wasnt that big of a deal.

Couple of tips tho:

1) Mix up some tranny fluid and acitone 50/50, and marinade any fittings and bolts/nuts after a light scrub with a wire brush. let um soak for a bit, half hour to a day depending on how rusty. This has saved me gross amounts of work/hastle and rounded off or busted fasteners. be aware: this mix WILL eat paint and plastic.

2) I removed the brake light switch, and the banjo bolt holding the distribution block to the back of the MC. I didnt even try touching the brake line fittings in the dist block. In my mind, that's just begging for trouble either kinking a line, or rounding off a flare nut.

3) after dissasembly, cleaning, I scrubbed the barrel of the barrel with a red scrubbie to take out the rust and smooth any minor pitting. made it nice and shiney as possible. I used plenty of Kerosene to clean with.

4) I installed the MC without filling it untill everything was hooked back up except the brake light switch. I used a MIPT x hose barb brass fitting in place of the brake light switch, and used a large 50cc syringe to vacuum bleed the MC. took some pumping of the pedal also with the syringe attatched to collect the fluid. Once it was bubble free I put the brake light switch back on and bled the rest of the system.

5)REPLACE ALL THE COPPER WASHERS WITH NEW. this will only cost you about $2 but it's cheap insurance.

enjoy and good luck. I hope these tips help.

 

I appreciate the tips. Rather than trying to rebuild, I will be replacing with a brand new unit. Since the bolts that secure the master cylinder to the frame look pretty rusty, just to be on the safe side, I may go ahead and order replacement bolts from Mid-Fifties.

 

Dumbluck, you are not supposed to clean brake parts with any kind of petroleum based solvent (i.e., kerosene). I trust you followed with plenty of brake parts cleaner, or your rubber seals will be toast pretty quick.

 

Although I haven't replaced the MC with the new one, I took a look around the boot to see if it was still seeping...it wasn't. So initially I thought it might have been some blow by oil or something else that may have resembled a leak. I checked the MC fluid level and it was half full so after filling it back up.....you guessed it..the seeping around the bottom boot is back. Gosh, I thought for a momment I wouldn't have to change it out! Even when it was half full, I had very good brake peddle.