My brakes basically hit the floorboard during a recent seattle area traffic close call moment in quite a while.

My "new" brakes were incredibly effective in that I stopped on a dime and avoided the rear end, the problem is I hit the end of the brake pedal travel and bounced brake pedal off the floorboard to do it.

It's not a great feeling man!

I have a 95' 2500 HD but put on a 99-01 front axle on it.The newer front calipers are a bit bigger dual piston and the old ones were single piston and probably required less fluid to operate.

Was wondering if a master cylinder from a 99-01, which would presumably push more fluid volume for the bigger dual piston calipers, would easily fit on my 95?

Pretty sure it's not air in the line . We bled, bled some more, and rebled those things.

Or am I thinking about this the wrong way? Suggestions?

 

I'd suggest that it sounds like you might have a broken rear brake line (check around the gas tank area, as the rear metal brake line is famous for rusting and leaking between the frame and the gas tank, which can be hard to see) or possibly a master cylinder going bad.

 

I ended up doing all new lines when I did the front axle swap. I had to fish the new line behind the tank and couldn't see back there and so I have never really been comfortablle about that.

I thought if it was leaking I would see bubbles when I'm bleeding it. I haven't been seeing any bubbles at all when I bleed it. Wouldn't I be seeing some bubbles from at least one the blee screws if it was leaking?

 

7500 or 8800 ? They both use different master cylinders. Don't know if the 99-01 8800 master cylinder is different or not. Look up the parts and see.

 

It's the 8800 one with the bigger brakes.

 

Thanks for mentioning that you've replaced all of the steel brake lines.

If all of the brake lines (flexible and steel lines) are properly sealed, I'd focus on the master cylinder. I have a '96 Ram 2500 4x4 HD with the 8800 lb front axle, however, I swapped out the rear axle to a later 2nd gen Dana 60 with disc brakes to improve my braking. I'm still using the original master cylinder and its working fine.

 

Sorry I disappeared for several hours. Working for a living....

I should have also mentioned both the master cylinder and brake booster both for the 95 8800lb HD brakes also got replaced when I was doing everything.

Lol maaybe now is the time to mention that the calipers and rear drum parts are all brand new too. I think everything might be new except some of the antilock stuff by the master cylinder.

I replaced everything when I redid my axle since I ended up putting longer lines out front and back and all the old stuff was kind of just disintegrating anyway.

I have no problem buying whatever might be better suited for the job if that would help.

 

What do you guys think? Can the 99-01 or maybe the '02 up HD master cylinder fit on there?

 

Personally, I would compare the specs on each one you're considering and go with the better one. I'd also include the earlier model 1995 master cylinder in the mix too for the comparison. I'm still running my original style 1996 master cylinder on my truck even after converting to a rear disc brake rear axle. The master cylinder reservoir for the front brakes is pretty large and the rear brake reservoir is much smaller, however, it seems to get the job done well. The diameter of the piston in the master cylinder is likely the most critical factor in braking performance in relation to the master cylinder.

 

Thanks for the input AtomicDog. You don't say it directly but I get the feeling you might think the original master cyclinder should probably work for me if I had everything working correctly. That line of thinking seems to jive with all the guys upgrading their 99-01 front brakes to gen 3 calipers and rotors never mentioning a need for a master cylinder upgrade that I have seen. Maybe I need to give it another look. Must be something funny going on.