Need Help with Rear Brakes.

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

smpoulin1

smpoulin1

Junior Member
Joined
Jan 24, 2016
Posts
29
Reaction score
7
Location
South Carolina
First Name
Steve
Truck Year
1985
Truck Model
C10 - Silverado
Engine Size
350
Need some help folks…Can’t seem to get fluid to my rear brakes and my brake light stays on. New proportioning valve (used centering tool to bleed), new master cylinder, blew lines out to ensure no obstructions and still can’t get fluid to the rear. Any ideas? Thanks in advance.
 
fast 99

fast 99

Full Access Member
Joined
Dec 31, 2021
Posts
2,018
Reaction score
2,918
Location
Spokane, Washington
First Name
Brian
Truck Year
81,85
Truck Model
K20
Engine Size
350
If the lines are clear verified with air from the master to rear cylinder bleeders either the master is bad or improper bleed procedure.

Could try using a NEW pump oil can filled with brake fluid with a piece of hose attached to a line at master. See if any fluid can be pumped back there.
 
Turbo4whl

Turbo4whl

Supporting Member
Supporting Member
Joined
Oct 30, 2019
Posts
3,121
Reaction score
7,243
Location
Downingtown, PA
First Name
Wayne
Truck Year
1974
Truck Model
Jimmy
Engine Size
350
If the rear brakes shoes are not adjusted out to the drums, then you will have trouble bleeding the rear cylinders. Remember the (self) automatic adjusters will only maintain the adjustment. When the shoes are way out of adjustment, the adjusters will not take up any slack.

One trick, to bleed out of adjusted rear shoes, apply the emergency brake. This moves the shoes to the drums. Then you can bleed them. If the e-brake pedal goes to the floor and the drums still turn, shoes are way out of adjustment.
 
Grit dog

Grit dog

Full Access Member
Joined
May 18, 2020
Posts
6,963
Reaction score
12,210
Location
Auburn, Washington
First Name
Todd
Truck Year
1986, 1977
Truck Model
K20, C10
Engine Size
454, 350
You said new master cylinder. Is it fully bench bled?
Could be the problem.
 
R

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
5,416
Reaction score
8,630
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
smpoulin1 said:
Need some help folks…Can’t seem to get fluid to my rear brakes and my brake light stays on. New proportioning valve (used centering tool to bleed), new master cylinder, blew lines out to ensure no obstructions and still can’t get fluid to the rear. Any ideas? Thanks in advance.
Click to expand...
Did you get fluid to the rear while you were bleeding the brakes
 
Dmack

Dmack

Full Access Member
Joined
Mar 13, 2019
Posts
333
Reaction score
436
Location
Central OR
First Name
Dave
Truck Year
1983
Truck Model
K20
Engine Size
350
You didn't say year/model. Some of the later HD trucks had a load sensing valve on the rear axle that can cause problems.
 
smpoulin1

smpoulin1

Junior Member
Joined
Jan 24, 2016
Posts
29
Reaction score
7
Location
South Carolina
First Name
Steve
Truck Year
1985
Truck Model
C10 - Silverado
Engine Size
350
Turbo4whl said:
If the rear brakes shoes are not adjusted out to the drums, then you will have trouble bleeding the rear cylinders. Remember the (self) automatic adjusters will only maintain the adjustment. When the shoes are way out of adjustment, the adjusters will not take up any slack.

One trick, to bleed out of adjusted rear shoes, apply the emergency brake. This moves the shoes to the drums. Then you can bleed them. If the e-brake pedal goes to the floor and the drums still turn, shoes are way out of adjustment.
Click to expand...
Nice tip, will check the adjustment. Thank you.
 
J

jtbartsch

Junior Member
Joined
Feb 1, 2024
Posts
6
Reaction score
5
Location
Overland Park, KS
First Name
Joseph
Truck Year
1986
Truck Model
K10
Engine Size
350, 5.7L
What you will need to do is crack the bleeder screws to the rear drums and perform a gravity bleed on both at the same time or individually. Let it sit overnight and check your clear tubing to see if there is fluid in the line. If so then you need to bleed brakes like normal. I just went through exactly what you are talking about and it was very frustrating to say the least.
 
Rustisbest

Rustisbest

Full Access Member
Joined
Jul 20, 2021
Posts
181
Reaction score
455
Location
Athens, TN
First Name
Matt
Truck Year
1979
Truck Model
C10
Engine Size
377
Pull out the bleeder screws and pump the pedal. Sometimes trash, rust, etc gets stuck in there and they won't bleed. I'd put new screws in while I was there too.
 
You must log in or register to reply here.

Similar threads

smpoulin1
Brake Issue
Replies
0
Views
174
smpoulin1
smpoulin1
K
Brakes
Replies
13
Views
954
ali_c20
ali_c20
B
Bleeding rear brakes on 1978 C30 dually
Replies
10
Views
549
bee man
B
P
Strange brake issue
Replies
3
Views
737
Ricko1966
R
P
Problem with New C10 Brake System
Replies
0
Views
787
Peter coppola
P

Latest posts

Forum statistics

Threads
44,129
Posts
949,921
Members
36,229
Latest member
CompyCarGuy
Top