brake pedal spongy

[jimraelee]

My brake master was leaking out the back so I replaced it... No big deal pull out the new master, clamp in vice, fill with fluid, allow to bleed thru, grab screw driver and work the plunger a little getting more air(while holding fingers over the brake line ports to keep air from sucking back). Install on truck and bleed the lines at master, then bleed all 4 wheels to ensure all air is removed. Well thats not working today. Brakes are spongy and I can pump them up to get somewhat of a pedal. Anyone know of any issues or tricks with these 91 F350's 4x4's??? I know there is a rear antilock actuator up almost under the master on the frame rail... I have bleed it there also and no air comes out.

 

[MARQ2277]

Tell me what year, and model and other information, and I will look in my chilton manuel for you.

Marq
_________________________________________
1990 Ford F-250 4X4:
7.3 IDI with 120K on the clock:
ATS Turbo with waste gate:
Stage One Injectors (Oregon Injector Service):
Complete Return Fuel Kit (Oregon Injector Service):
DB2 Pump, cranked up with Cold Advance wired permanently on:
4” down pipe, 4” straight through exhaust stopping between cab and bed (no **** on my stuff):
Torque Converter Lock Up Switch (On/Off/Lock-Up):
E4OD Line Pressure Controller (adjusted to fast/firm shifts):
4” lift w/Rancho shocks:
Big Fat Tires on custom rims:

Tows 1985 fully loaded heavy 28 foot RV (my house) everywhere:

 

[LCAM-01XA]

Marq, he said it in his post - tis a '91 F350 4x4.

Jim, I've always had best results when I screw in barb-hose fittings in the brake line ports, then run hoses from those up to the reservoir so that the ends are always submerged in brake fluid. Pumping it this way automatically purges all the air out, and suck fluid in from both ends of the pistons in the main bore. Also, I never do it on the vice, partly cause I ain't got one - always in the truck, with slow and careful pedal motion, I know that ain't how tis supposed to be done but it never ever failed me.

 

[jimraelee]

Well MLSC... if it works for ya, than dont switch right??? Yes back in the day we did it on the bench vise with the (then supplied with new masters) the screw in fittings and hose's I'm getting so desperate that I want to start getting some fittings to cap off the end of each brake line and then start eliminating components. I have crimped the rear brake line and seems no change in pedal stiffness...

 

[MARQ2277]

OOPs, my bad, so it is a 91. Okay, let me check the book and see if we can shed light on the issue.

Marq
_________________________________________________
1990 Ford F-250 4X4:
7.3 IDI with 120K on the clock:
ATS Turbo with waste gate:
Stage One Injectors (Oregon Injector Service):
Complete Return Fuel Kit (Oregon Injector Service):
DB2 Pump, cranked up with Cold Advance wired permanently on:
4” down pipe, 4” straight through exhaust stopping between cab and bed (no **** on my stuff):
Torque Converter Lock Up Switch (On/Off/Lock-Up):
E4OD Line Pressure Controller (adjusted to fast/firm shifts):
4” lift w/Rancho shocks:
Big Fat Tires on custom rims:

Tows 1985 fully loaded heavy 28 foot RV (my house) everywhere:

 

[creighta]

I use a blow gun w/ the vacuum port on the side when I can't get air out of the system. If you do this you may want a respirator bc the fluid comes out in a really fine mist.


W/ the master, though I don't know how well this method would work.

 

[jimraelee]

Well 1.5 bottles later, bleeding on the flat and on the inclined driveway, then back on the flat ( as should be, bleeders are set to be the high point) and seems ok now. Glad the daughters leg held up.... Shes a trooper.

 

[LCAM-01XA]

Jim, what brand is your master cylinder? The Fenco ones that AutoZone carries are done in Kanadia and ALWAYS come with the barb fittings and hoses, not so much the case with Cardone and the other players in that game. It also so just happens that I ain't never had a problem with a master remaned by Fenco, whereas Cardone ain't nothing but bad luck.

 

[jimraelee]

It was actually a NAPA master, now the rear cylinders I got from autozone... well I installed them both, and when I started to bleed them, the right side poured out fluid. Pulled the drum to find that it was leaking past the cups inside the rubber boots...

 

[LCAM-01XA]

So you got new wheel cylinders now? Or it was one of the new ones that was faulty out the box and leaked on you? In any case, I take it tis both are good now?

 

[adam g]

put a master cylinder on from an f-450. It will give you bigger master and better pedal.

 

[jimraelee]

I replaced the cylinders in the rear because the right side, every time I opened the bleeder it would spurt out an air bubble.... replaced both rears, and the right side (new) blew fluid past the diaphragm/plunger inside. Yes all is good now. I have a nice high and tight pedal.
ADAM, thanks for the tip... I was curious about upgrades. hopefully I wont need a 3rd cylinder for a while.

 

[MARQ2277]

Cool. I was having trouble finding anything that you probably did not already know. Being an electrician, I did work in a engine rebuild shop long time ago, for a number of years, and I can take a transmission apart and put it back together with no problems, but don't have much time on brakes, you guys know a lot more than me there.

Marq
___________________________
1990 Ford F-250 4X4:
7.3 IDI with 120K on the clock:
ATS Turbo with waste gate:
Stage One Injectors (Oregon Injector Service):
Complete Return Fuel Kit (Oregon Injector Service):
DB2 Pump, cranked up with Cold Advance wired permanently on:
4” down pipe, 4” straight through exhaust stopping between cab and bed (no **** on my stuff):
Torque Converter Lock Up Switch (On/Off/Lock-Up):
E4OD Line Pressure Controller (adjusted to fast/firm shifts):
4” lift w/Rancho shocks:
Big Fat Tires on custom rims:

Tows 1985 fully loaded heavy 28 foot RV (my house) everywhere:

 

[towcat]

Well 1.5 bottles later, bleeding on the flat and on the inclined driveway, then back on the flat ( as should be, bleeders are set to be the high point) and seems ok now. Glad the daughters leg held up.... Shes a trooper.

isn't child labor great?
when they're done for the day, they can be easily bribed for payment by a trip to the ice cream store

 

[towcat]

my trick for bleeding these trucks involves a 12pack and a couple quarts of brake fluid.
I start with opening up the abs bleeder and have a beer or two while letting it gravity bleed. when no bubbles come out, close it off and open up the furthest bleed screw and have a few more beers watching it gravity.....you get the idea i've found that the dump valves on the abs like to trap air bubbles and the best way to get them out is by opening up the bleeders and letting them get out on their own. having a few beers helps the patience factor