Brake fade

[Robertgjr]

Hello everyone, new to this forum and have a question regarding brake fade on a 1994 Dodge Ram 3500 Dually with the 5.9 Cummins engine. Ok, replaced both front calipers and both rubber brake hoses and master cylinder(twice). Bled the complete system, rr, lr, rf and lf and brakes still fade. When you pump up the pedal it will hold then start to fade to the floor. Now when we bleed the system again(about 3-4 times now) after doing the back the pedal feels good but has fade. When we bleed the front the pedal goes down to the floor. We ended up taking calipers back and getting new ones (again) but still the same issue. We were thinking about replacing the proportioning valve but we couldn’t find one, even tried the Dodge dealer. Have any of you had this issue before, if so what was the solution ? Thanks in advance for any and all comments, suggestions and feedback.

 

[tron67j]

Could be heat build up. Are you carrying heavy loads, is the truck set up with a lot of heavy items like bull bars, rear bumper that is heavy, engine lift or other heavy items regularly carried? The majority of braking occurs with front wheels, are rears wearing out faster? That could signal a problem with master cylinder like seals, etc. that cause them to work harder.

 

[Daw14]

Does it have abs ? If so that may need some work.

 

[Robertgjr]

Could be heat build up. Are you carrying heavy loads, is the truck set up with a lot of heavy items like bull bars, rear bumper that is heavy, engine lift or other heavy items regularly carried? The majority of braking occurs with front wheels, are rears wearing out faster? That could signal a problem with master cylinder like seals, etc. that cause them to work harder.

It’s basically a standard truck, nothing added and it hasn’t been used since parts were installed due to the brake fade. Don’t want to take any chances.

 

[Robertgjr]

Does it have abs ? If so that may need some work.

This is something we are going to look into tomorrow since a buddy of ours mentioned it. Thanks

 

[G/T jonny]

Classic signs of master cylinder issues. fluid leaking past the piston seal. If brake fluid isn’t squirting out of somewhere it’s leaking by the master cylinder piston, causing the pedal to drop. I see you already replaced it. (Twice) I don’t know what’s going on there. Always use new hydraulic parts never reconditioned or rebuilt.

 

[Sherman Bird]

Hello everyone, new to this forum and have a question regarding brake fade on a 1994 Dodge Ram 3500 Dually with the 5.9 Cummins engine. Ok, replaced both front calipers and both rubber brake hoses and master cylinder(twice). Bled the complete system, rr, lr, rf and lf and brakes still fade. When you pump up the pedal it will hold then start to fade to the floor. Now when we bleed the system again(about 3-4 times now) after doing the back the pedal feels good but has fade. When we bleed the front the pedal goes down to the floor. We ended up taking calipers back and getting new ones (again) but still the same issue. We were thinking about replacing the proportioning valve but we couldn’t find one, even tried the Dodge dealer. Have any of you had this issue before, if so what was the solution ? Thanks in advance for any and all comments, suggestions and feedback.

Make SURE you haven't put the caliper on upside down. This is accidentally done all the time by techs. The left and right calipers CAN interchange and wind up upside down. The bleeder screw being low on the caliper is your tell.

I learned this the hard way back in 1976. After wasting 2 gallons of fluid, I finally figured it out.
Since then I have seen numerous guys make the same mistake!

 

[Ermio]

Hello everyone, new to this forum and have a question regarding brake fade on a 1994 Dodge Ram 3500 Dually with the 5.9 Cummins engine. Ok, replaced both front calipers and both rubber brake hoses and master cylinder(twice). Bled the complete system, rr, lr, rf and lf and brakes still fade. When you pump up the pedal it will hold then start to fade to the floor. Now when we bleed the system again(about 3-4 times now) after doing the back the pedal feels good but has fade. When we bleed the front the pedal goes down to the floor. We ended up taking calipers back and getting new ones (again) but still the same issue. We were thinking about replacing the proportioning valve but we couldn’t find one, even tried the Dodge dealer. Have any of you had this issue before, if so what was the solution ? Thanks in advance for any and all comments, suggestions and feedback.

Try the master cylinder