Spongy Brake Pedal

Marcos Beltran · Jan 5, 2024

Have a 96 GMC single cab V6 stepside. Already did the MC upgrade. Parked the truck, went on vacation for 5 days, came back and tried to drive the truck and had no brakes. Pedal would go all the way to the floor. Looked underneath and there isn' t any visible fluid leaks. Do not hear any vacuum leaks either. Any ideas what could have caused this? Brakes worked awesome before parking it. Cant imagine something could of got damaged from it being parked.

movietvet · Jan 5, 2024

You may/likely have air in the system. Try bleeding the brakes again. How did you bleed the brakes before? What was the process?

Marcos Beltran · Jan 5, 2024

I did the typical bleeding, start from back to front. MC was upgraded over 3 years ago. Everything worked fine, good pedal feel, no problems at all till the time i parked it for a few days.

movietvet · Jan 5, 2024

The first place to start is bleeding again.

You have already looked for leaks. Unbolt the master cylinder and look to see if there is fluid in the back cavity area. That would indicate a leak at the back seal area.

Was the fluid low at all when you inspected?

Marcos Beltran · Jan 5, 2024

Fluid level was/is at the right level.

Caman96 · Jan 5, 2024

Was MC bench bled? Which MC upgrade did you use?

Orpedcrow · Jan 5, 2024

If it’s 3 years old with no issues, fluid level is normal, no leaks, then it should be a bad diaphragm in the master.

movietvet · Jan 5, 2024

Orpedcrow said:
If it’s 3 years old with no issues, fluid level is normal, no leaks, then it should be a bad diaphragm in the master.

Yes, it could be bypassing internally and not leaking out of the back. Hard to believe that it happened just sitting there but could it, yes. I still say that should try to bleed first and see what happens.

Caman96 · Jan 5, 2024

Also, could be air in ABS. :shrug:

Caman96 · Jan 5, 2024

Sometimes I get air in my ABS, and I get gas! :flamingdevil:

Spongy Brake Pedal

Marcos Beltran

OBS Enthusiast

movietvet

Supporting Member

Marcos Beltran

OBS Enthusiast

movietvet

Supporting Member

Marcos Beltran

OBS Enthusiast

Caman96

OEM Baby!

Orpedcrow

I don’t know what I’m doing

movietvet

Supporting Member

Caman96

OEM Baby!

Caman96

OEM Baby!

Similar threads

Latest posts

Members online

Forum statistics

Share this page