72 k5, sons first truck build.(officially NOT mine now..)

[shady]

getting ALOT closer.... had to weld a bunch of holes I didn't see in the fender.... no idea how I missed those .

 

[shady]

next is door gaps... not bad considering I did all shimming by guess and cut all my body braces off today

 

[shady]

we got this thing running..... then i almost killed myself with it Somehow i got the shift linkage at tranny put in backwards and it was in low gear instead of park when we started it I happened to be infront of it on a ladder while it idled in place and didnt realize it was in gear till i reached up and goosed it..... it moved and did i forget to mention the brakes dont work yet for some reason....... I got lucky all i did was fall off the ladder and it coasted to a stop

 

[AJMBLAZER]

Eesh. Glad you're okay man.

 

[shady]

really got to figure out the brakes..... they were all new, I gravity fed all the air out through the lines individually.... but theres NO pedal pressure. cant even pump it up... plus about half way through the pedal stroke theres a loud pop and the pedal falls even faster..... everything is new except the booster. gonna crack a bleeder and pump the hell out of it to see if any more air comes out

 

[70jimmy]

Yep sounds like a bad vac booster to me. You also might try adjusting the rod travel on the front. Also check the grommet on the passenger side of the booster, they can get old brittle and allow air to escape = Bad Day.

 

[shady]

I cant imagine what it would feel like at the pedal if it was running... it all worked great when it went in the garage I only changed the master because I figured everything else was new, might as well. then I threw the old one away

 

[shady]

I made a weed sprayer pressure bleeder. bled it 3 times. and still no stoppy im lost. my kid and his friends call this thing 'Truck Norris'...... and its fitting cause it's KICKIN MY A$$

 

[82355]

Did you bench bleed the master?

Martin

 

[Chief Brody]

is the booster diaphragm bad?

 

[Chief Brody]

have you tried the old fashioned method of one person pumping the pedal while another is at the brake line fitting, opening just a quarter turn and going to each one....will need a quart or two of fluid to "push" out the air that way.

You might have a kinked brake line too...

 

[shady]

Did you bench bleed the master?

Martin

Yep

is the booster diaphragm bad?

Not sure.... im doing all this without it running, but im gonna see what happens if I replace the booster with a solid rod for a test.

have you tried the old fashioned method of one person pumping the pedal while another is at the brake line fitting, opening just a quarter turn and going to each one....will need a quart or two of fluid to "push" out the air that way.

You might have a kinked brake line too...

gonna resort to that method soon but it doesn't pump up so not sure if that will work

 

[SUPER'BURB]

Not sure.... im doing all this without it running, but im gonna see what happens if I replace the booster with a solid rod for a test.

I might be wrong but don't you need to have the truck running to bleed a boosted brake system??

I could be wrong but I always have mine running while I bleed.

 

[shady]

my rod idea wont work because the master bolts to the booster

all doing it running does is help push the pedal down all the way repeatedly IIRC.... that job would have all our legs looking like tree trunks if you did it non boosted every time. I just get 'straight to the floor' as is without even running.... and running hasn't made a difference so far... we did pull it out in the driveway and let it run to check/fill fluids.... had to stop by shutting it off. and push the rest of the way... wasn't gonna stop if I didn't.

pumping the brakes makes no difference in the feel.... so i cant pump them up and get pressure.... tried till my leg got tired.

its gotta be down to bad new master or booster eff'd as far as i can tell...

im gonna pressure bleed the p1$$ out of it again for giggles too...... like open a bleeder and let it flow till the pressure nearly dies and do it again, then move to the next wheel.

 

[Chief Brody]

is the master cylinder a reman'd USA one or is it a chinese rebuilt?

 

[shady]

never even looked into it... they had a $17 one and a $90 one I just took the $90 one. never really looked anywhere else

BrakeBest® Select™ - Brake Master Cylinder

http://www.oreillyauto.com/site/c/d...k=Search_01292_1029259_810&pt=01292&ppt=C0066

 

[y5mgisi]

If it's going to the floor with no pressure, it's not the booster. I think it's a bad master. Could be a broken rod somewhere, to test it, I would Crack one of the breeders on the calipers and press the brakes. See if fluid comes out in proportion to the brakes being pressed. I'm guessing you don't have the old master still?

 

[y5mgisi]

Also, you could un bolt the master from the boosterand bbrass the brakes and make sure the rod travels appropriately for.

 

[shady]

yeah thats my next step is pull the master and see how far the rod is moving. im also gonna see if i can push it in with a stick or something... if i can move it that way its in the master or lines.... and yeah unfortunetly i through the old master out

 

[shady]

ended up being a REALLY deep socket for the booster rod in the back of the master.... wrong master I guess. ordered for this truck I filled the gap with a bolt and I got AWESOME brakes gonna take it to orielly's and get them to get me the right one.