Hi All

[Snowman671]

Hi All Need a Bit Of Help

First Off Hello Everyone !!

I am now a member of 3 of these boards about FORD Diesels. I have learned much more than i ever need to now and now I have worries i never had about the truck I bought. I will endure tho as I know Diesel is the only way to go even with the prices of it as of late.


Anyways I Do hav e aproblem and not sure what next step is.

Brake Petal Fade :

Components Replaced So far....

Master Cyl.
Front Calipers
Rear Cylinders
Rear Shoes
New Parking Brake cables


Ok. now I bled the hell outa this system and it still fades away. truck stops but when sitting it fades towards the floor..

I have read it could be the RABS Valve and Also could be the Vacume Pump.

So I propose the question which is most likely answer I don't think i can have any air in the lines i have ran over a gallon of fluid thu the system in various manners : Vaccume bleed, good ole manual bleed, and tube in bottle of fluid bleed etc.

truck has 135k on the odometer and i don't think the PO took very good care of it but it didn't have any rust and it is the size of truck I needed so I bought it. I don't mind spending money to fix it I just don't want to toss parts at it.


one more thign anyone know what the normal operatiig temp is i only have idiot guage not real temp guage..

thanks guys
Dave

ps here is a pic... not good but one anyways

 

[Joe Mc]

What was the problem that started all of this?

Did you bench bleed the master cylinder?

You are to the point of tracing the lines, take your time and let it fade 7 of 8 times, then trace all the lines checking for wet spots.

If you can't find a leak then it is time to check your new parts, just because it is new does not guaranty that it is good. Mine had a slow fade onetime with no leaks, it was a small hole in one of the cups of the master cylinder.

Nice looking truck!

 

[Snowman671]

What started it...

Umm Bought the truck checked brakes didn't like them and petal had fade... I removed back drums seen oil laeking from seals decided to replace seals and shoes becuase they are junk said hey 12.00 more for cyls and put them in as well, went to bleed brakes front had never been touched so the bleeder broke off so bought new front calipers and still ahd trouble so I bought reman MC and proceeded to bleed them all again. bench bleed the MC 3 times and when it its capped off it feels great ! once on the truck feels liek crap and fades out...

so bleed from back first then the RABS valve then the fronts.. bled the mc again on the truck.. still feel like crap....

I just bought the trcuk and have drov eit liek maybe 50 miles now until i get the brakes figured out cant do much more than that need to get inspection sticke ron it my friend is a insp mechanic and owns his own garage and we can't figure it out.

he's a stickler wont pass the truck until it is right !! (costs me money but I feel better if everythign is good.).

I'v checked all the lines clean and dry...

thansk for the complements trucks in nice shape jus thave to work the bugs out.

My laundry list of repairs for the last month sense i bought it.

Removed Bedliner and covered it in Rhino Lining
Waxed truck
Cleaned interior (not a tear in it and seats are perfect)
Replaced front Ball joints upper / lower
repleced front axles u-joints
replaced front seals
replaced front calipers
replaced rear seals
replaced rear cylinders
replaced shoes
turned drums
replaced parking brake cables
new Eagle Alloy Wheels and KUMHO 305/70/16 Tires
new glow plugs
(found oil underside of motor will start on them leaks soon)
prepping a EZ-Dump bed to slide in the back ( Rhino lining that baby first tho)

I paid 5k for the truck and no rust on it except the frame a little normal rust. I'm planning on pulling my 31' trailer with it so I am doing everything....

More pictures soon....

Thanks
Dave

 

[h2odrx]

would vacuum play here?
WOW nice truck!!!
maybe time to find a new inspection friend?

looks like you need a bigger garage?

 

[Snowman671]

Na keeping my buddie we build race cars and stuff together his garage is 2 bays that fit 4 cars or 2 cars on 1 side and a car on lift way up so I can get the truck in..


he don't charge me to do anything but he is a real sticker on BRAKES.. anythign else he would le tme slide on but not Brakes.....

I'll get more pictures tonight on the way home the Sun is out today here in PA so it shodul show nice

Vaccume is next route I'm going to put a guage on it see what i read at the power booster..

thanks !!

 

[Mr_Roboto]

Vacuum pump will not cause fade. It only gives vacuum to the brake booster.

Bypass the RABS valve. If that solves the problem, you have found your leak.

By "fade" I assume you mean that the brake pedal slowly sinks to the floor...

 

[Joe Mc]

I agree with your buddy, brakes are the most important part of the truck.

It is sort of a pain, but at this point I would isolate the master cylinder by removing the lines and installing metal plugs in the line ports. Then I would see if the master cylinder would leak down. Then you can hook up one line at a time to see if the trouble is in the front brakes or the rear brakes. That is the way I would do it, break the system into sections to try and isolate the problem. Or you could wait awhile and see if someone else has had this same problem and knows the quick answer.

Good Luck,

Let us know what you find.

 

[82fordtruck]

I think that is normal in these trucks. There is a zero loss booster that you can get - I know little about them. Maybe someone'll pipe up here.

 

[icanfixall]

The reason your peddle slowly sinks is because the rear automatic adjusters don't work much at all. Try this. With the truck parked and motor running apply the emergancy brake peddle. How far down does it go before it holds? Now put your foot on the brakes and press down like your trying to stop the truck. Does the peddle sink? What most of us do is manually adjust the rear brakes when we see the brake peddle slowly sinking or when it stops the truck around half way to the floor. Sure, the rabs valve could be at fault but that will cost you around $300.00 just to find out it wasn't the problem. The rear shoes need to be about .025 from the drum to be adjusted properly. This is very hard to measure but thats the way it works best. When the rear brakes are out of adjustment the fronts do all of the stopping and will overheat. I waisted several front rotors and pads till I found this out. Ford didn't have a better idea on these self adjusters.

 

[94f450sd]

replace your rear drums.my f350 did the same thing as yours.i did the same as you.i did master cylinder,wheel cylinders,calipers,rotors,brake booster,rear shoes,rear hardware,front rubber brake hoses,rear brake hose,beld the system many times.i went through 2 gallons of fluid bleeding it.

when i did my rear end swap i used all the brake parts from the old rear with the much better drums that were on the new rear and no more pedal fade

 

[Mont91]

Wore out drums, impropperly adjusted rear brakes(you should be able to hear them kissing the drum at least when properly adjusted), Parking brake not releasing all the way, RABS unit bad. There is a buliten on the RABS unit causing a sinking pedal. My first thought is rear shoe adjustment.

 

[Mr_Roboto]

OK, are we talking about a sinking pedal or are we talking about heat fade, i.e. the brakes require higher pedal force to stop the same when they heat up.....

 

[ericboutin]

When mine did this it ultimately turned out to be the RABS valve. And yes it is like 300 bucks! Good luck!

 

[Russ]

Can't help with the problem but if you ever decide to part with your truck keep me in mind. It's just what I've been looking for.

 

[troutwest66]

"Snowman! This is the Bandit, son!" Just kidding. Love that movie. Great looking truck. Manual or auto tranny? You know you got put a turbo on that now??!! Once you get the brakes figured out you'll love this truck! Welcome to Oilburners. You won't find a more comprehensive source of information than right here. There are many other sites on diesels but you won't get as good as info as here. I've been to the other sites and the guys with no attitudes are here! Enjoy the truck!