Brake vacuum leak?
Thread Starter
|
Mountain Pass
Joined: Jul 2017
Posts: 161
Likes: 2
From: North Salt Lake, UT
Brake vacuum leak?
Brake pedal went to the floor when my wife was driving the truck (with the kids on-board!) Buy cane back enough to get her home.
Brake fluid was pretty low, so filled that back up to ¼” from the top as per owners manual. Brake pedal still goes to floor.
When I press the pedal, I can gear a shirt hiss sound as in this video - vacuum leak? What could it be to be so clear from inside the cab?
Brake fluid was pretty low, so filled that back up to ¼” from the top as per owners manual. Brake pedal still goes to floor.
When I press the pedal, I can gear a shirt hiss sound as in this video - vacuum leak? What could it be to be so clear from inside the cab?
Grumpy goat
Joined: May 2017
Posts: 3,058
Likes: 594
Booster going out usually gives a hard pedal. I'd be looking at master cylinder piston seal issue. Brake fluid will bypass and give a pedal like what you have. Now I'm assuming you don't have fluid leaking onto the ground somewhere
Fleet Owner
Joined: Jan 2004
Posts: 26,007
Likes: 575
From: Brentwood,CA
Brake fluid doesn't disappear for no reason, where did it go? Some fluid drop is normal for brake lining wear. Its common for the master cylinder to leak into the booster and the brake fluid gets pulled into the engine and burned. The rubber in the brake booster cannot tolerate brake fluid and it can't be cleaned as mentioned. I suggest removing the master cylinder and inspecting.
Thread Starter
|
Mountain Pass
Joined: Jul 2017
Posts: 161
Likes: 2
From: North Salt Lake, UT
So, thinking it would be safer to replaced it all for future proofing:
F250 SCLB w/460
Front RH brake hose D5TZ-2078-A (LMC 45-4439 $27.95)
Front LH brake hose D5TZ-2078-G (LMC 45-4438 $27.95)
Rear brake hose (LMC 45-4454 $34.95)
Stainless Steel brake line kit (LMC 45-4673 $199.95)
Assorted clips
Rear drums and wheel cylinders etc
For the rotors, pads, booster, and master cylinder, I'll have to check if I have single- or dual-piston front calipers (GVWR of 7100, so probably dual..). Might convert to F350 dual-diaphragm booster and appropriate M/C.
F250 SCLB w/460
Front RH brake hose D5TZ-2078-A (LMC 45-4439 $27.95)
Front LH brake hose D5TZ-2078-G (LMC 45-4438 $27.95)
Rear brake hose (LMC 45-4454 $34.95)
Stainless Steel brake line kit (LMC 45-4673 $199.95)
Assorted clips
Rear drums and wheel cylinders etc
For the rotors, pads, booster, and master cylinder, I'll have to check if I have single- or dual-piston front calipers (GVWR of 7100, so probably dual..). Might convert to F350 dual-diaphragm booster and appropriate M/C.
Thread
Thread Starter
Forum
Replies
Last Post
caaront
1987 - 1996 F150 & Larger F-Series Trucks
5
Jul 11, 2014 11:16 PM
