No line pressure to rear disc conversion, no prop valve

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.

R

roger0080

Junior Member
Joined
Sep 6, 2014
Posts
12
Reaction score
18
Location
Minnesota
First Name
Roger
Truck Year
1977
Truck Model
C10
Engine Size
350
Check the pedal rod adjustment. If is extended to long, it will push the master cylinder pistons past the rear line outlet effectively blocking that port, thus no pressure at the rears. Had this experience once on a used pickup I bought. Had fronts yes, rears no.
 
S

sctaylor

Junior Member
Joined
Aug 23, 2024
Posts
10
Reaction score
3
Location
Indiana
First Name
Scott
Truck Year
1988
Truck Model
R20
Engine Size
350
Update:
Disc/ disc Mc & p-valve installed & bled (bench, then pressurized, then vacuum pump). Pedal still soft & zero caliper action front or rear. Next up is rotating the rear calipers (mounting bracket) forward to see if I'm trapping air.
Thx again for the help.
 
B

Bennyt

Full Access Member
Joined
May 17, 2019
Posts
1,202
Reaction score
1,858
Location
Surprise
First Name
Ben
Truck Year
1977
Truck Model
C10
Engine Size
350
sctaylor said:
Update:
Disc/ disc Mc & p-valve installed & bled (bench, then pressurized, then vacuum pump). Pedal still soft & zero caliper action front or rear. Next up is rotating the rear calipers (mounting bracket) forward to see if I'm trapping air.
Thx again for the help.
Click to expand...
On my K5, D60/14BFF, I actually mounted my calipers upside down so the p-brake cables went over axle for ground clearance. To bleed, I would remove calipers from bracket and hold upside down with a 2x4 in between to bleed.
 
S

sctaylor

Junior Member
Joined
Aug 23, 2024
Posts
10
Reaction score
3
Location
Indiana
First Name
Scott
Truck Year
1988
Truck Model
R20
Engine Size
350
Wound up keeping the position & swapping sides. E brakes are unhooked (ratchet pedal may be toast). Hose now enters caliper below bleeder, which is horizontal but on top. That's the best positioning I can figure out, keeping the calipers above the hub (still a truck). Still gotta bleed more, but finally got some pedal resistance. woo-hoo!
 
You must log in or register to reply here.

Similar threads

S
Rear disc conversion with hydroboost system
Replies
13
Views
3K
wlwarnke
wlwarnke
T
Replacing front brake lines - remove proportioning valve?
Replies
3
Views
936
legopnuematic
legopnuematic
J
Bad Proportioning Valve?
2
Replies
16
Views
2K
Cyrillious
Cyrillious
Bullet Bob
No brakes and unable to get one side to bleed
Replies
4
Views
974
Bullet Bob
Bullet Bob
1
Proportioning valve vs. load sensing valve
2
Replies
21
Views
3K
AuroraGirl
AuroraGirl

Latest posts

Forum statistics

Threads
44,209
Posts
951,804
Members
36,354
Latest member
KenLambert
Top