Brake Issue - Competition Diesel.Com

takedown95 · 11-29-2021, 12:25 PM

Hey CompD. My nephew has a 1996 2500. He recently had some brake work done including having rotors and pads replaced and installation of some new brake lines.

After he had the work done the truck is difficult to stop and when you push on the brake pedal the brake pedal makes some whooshing noise and goes down about 1-2" but then is firm. You can push it further than that but the brake pedal is firm at that point but the stopping power doesn't increase. If you are driving and really push hard on the brakes quickly it will slow down the truck relatively well. If I pump the brakes at low speeds it does increase the braking power. There doesn't seem to be any fade. If I do a brake stand it seems to push through the brakes fairly easily.

We did pull the front and rear wheels. The fronts looked good and the pads are engaging the rotor. We bled brakes again and their was no air in the lines. When we pulled the rears the brake pads and drum were very wet. It's unclear if the brakes are leaking or if its the wheel seal. The differential seems to be full of oil and the brake fluid reservoir level doesn't seem to be falling.

I'm down to the brake cylinder leaking or the brake booster failing but was curious what others thought?

Thanks.

bateman · 11-29-2021, 01:13 PM

If It is not an actual fluid leak I would pay attention the hose and fitting from vacuum pump and check the booster out. The noise you describe kind of sounds like a bad booster diaphragm

BigPapa · 11-29-2021, 01:21 PM

Sounds like you have no vacuum to the booster. Check the hose, plastic lines, and the check valve. It's common for the rubber boot at the vacuum pump to dry rot and may need replacing, and the plastic lines will break if you look at them hard. I rebuilt mine with nylon air brake tubing and vacuum hose. I've used a Dorman 47092 1/4" Vacuum Elbow to replace the boot at the pump.

TREED by bateman......

takedown95 · 11-29-2021, 02:00 PM

Thanks. That confirms what I was thinking too.

Whitenightmare · 11-29-2021, 05:47 PM

Did the brakes fade prior to the new parts? Were the lines replaced because they rusted out and leaked or preventative maintenance because they looked bad? Pull the rubber boots back on the wheel cylinders and see if there’s fluid in them.

11-29-2021, 12:25 PM	#1
takedown95 Name: takedown95 Title: Too Much Time Status: Not Here Join Date: Aug 2011 Member`s Gallery Posts: 2,841	Brake Issue Hey CompD. My nephew has a 1996 2500. He recently had some brake work done including having rotors and pads replaced and installation of some new brake lines. After he had the work done the truck is difficult to stop and when you push on the brake pedal the brake pedal makes some whooshing noise and goes down about 1-2" but then is firm. You can push it further than that but the brake pedal is firm at that point but the stopping power doesn't increase. If you are driving and really push hard on the brakes quickly it will slow down the truck relatively well. If I pump the brakes at low speeds it does increase the braking power. There doesn't seem to be any fade. If I do a brake stand it seems to push through the brakes fairly easily. We did pull the front and rear wheels. The fronts looked good and the pads are engaging the rotor. We bled brakes again and their was no air in the lines. When we pulled the rears the brake pads and drum were very wet. It's unclear if the brakes are leaking or if its the wheel seal. The differential seems to be full of oil and the brake fluid reservoir level doesn't seem to be falling. I'm down to the brake cylinder leaking or the brake booster failing but was curious what others thought? Thanks.

11-29-2021, 01:21 PM	#3
BigPapa Name: BigPapa Title: Truckless Status: Here Join Date: Jan 2008 Location: Springfield, TN Member`s Gallery Posts: 5,038	Sounds like you have no vacuum to the booster. Check the hose, plastic lines, and the check valve. It's common for the rubber boot at the vacuum pump to dry rot and may need replacing, and the plastic lines will break if you look at them hard. I rebuilt mine with nylon air brake tubing and vacuum hose. I've used a Dorman 47092 1/4" Vacuum Elbow to replace the boot at the pump. TREED by bateman...... __________________ Scott 2003 Avalanche Z71 Common sense is like deodorant. The people that need it most never use it.

11-29-2021, 01:13 PM	#2
bateman Name: bateman Title: Too Much Time Status: Not Here Join Date: Feb 2019 Location: Alabama Member`s Gallery Posts: 2,672	If It is not an actual fluid leak I would pay attention the hose and fitting from vacuum pump and check the booster out. The noise you describe kind of sounds like a bad booster diaphragm

11-29-2021, 02:00 PM	#4
takedown95 Name: takedown95 Title: Too Much Time Status: Not Here Join Date: Aug 2011 Member`s Gallery Posts: 2,841	Thanks. That confirms what I was thinking too.

11-29-2021, 05:47 PM	#5
Whitenightmare Name: Whitenightmare Title: Green Behind the Ears Status: Not Here Join Date: Jan 2020 Location: Chester county, Pennsylvania Member`s Gallery Posts: 55	Did the brakes fade prior to the new parts? Were the lines replaced because they rusted out and leaked or preventative maintenance because they looked bad? Pull the rubber boots back on the wheel cylinders and see if there’s fluid in them.