'78 K20 - RootBreaker from 1990 - nov 2025 8.1L not runnin

[RootBreaker]

so fixed exhaust, set timing (was at 38 degrees!!!) and took it for a spin to my sons school.
well I had to fight it as it just wanted to go left. got to school, picked him up and he was all smiles. head to sams club as we were doing a fundraiser and truck acted up totally. faught me all the way there and when shifting... once I got in 3rd (L-1-2-3), it would slow down and id give more gas and it would bogg... well let it sit during raiser and went back to it in 20 minutes and smoke was coming from the drivers caliper. Well that is why it was fighting me. so let it cool down and figured would let it limp home but instead seemed like caliper freed up... woot.

got on highway and started home. light turned red and as I hit brakes, she went all over the lane from left to right to lift to right.. was bit scarey.... so I just timed the lights on the way home. Got home and jacked truck up, took tires off, removed calipers and the drivers side boot/gasket round the piston was gone. Filled with sand, mud and other road/off road crud. Ran out and bought 2 new calipers.

need to get them on, bled then onto the back where I'm going to replace the pads and get that ebrake working correctly...

 

[RootBreaker]

So got truck running nice. Found a huge vacuum leak!!! Whatta difference. Question...
If i rev truck... fuel comes out of this gasket... wth!!!!

Ehat could it be?

 

[TreeFarm]

So got truck running nice. Found a huge vacuum leak!!! Whatta difference. Question...
If i rev truck... fuel comes out of this gasket... wth!!!!

Ehat could it be?

View attachment 248028

accelerator pump is right above that, its the leaver actuated by that red spring. could be leaking and runnign down

 

[RootBreaker]

accelerator pump is right above that, its the leaver actuated by that red spring. could be leaking and runnign down

Maybe.. but i rev and looks like swells out of gasket. Maybe tomorrow ill do video.. will get it though...

 

[nvrenuf]

Is that rtv?

 

[RootBreaker]

Is that rtv?

lol NO!!!!
it is the gasket with absorbed fuel... thus why so puffy...

I'm clueless... figure ill buy the blue gaskets for the front bowl and a new holley gasket fro under the carb, between the carb and adapter.

 

[TreeFarm]

fel pro makes the best carb gasket. they make a rubber coated gasket that kind of glues the two surfaces when it gets hot

 

[RootBreaker]

Replaced carb gasket.. nope... so has to be front bowl or accelerator pump gasket... grrrr

 

[Bent77]

Well you have to replace one to get the other, so get them both

 

[RootBreaker]

Well you have to replace one to get the other, so get them both

I'm a dummy on carbs, well know a little.. hah..

I thought the accel pump gasket is on the bottom and the bowl gasket goes around the bowl... so you don't need to do both at the same time?

 

[Ned Kelly]

I think there is a good youtube vid on re-assemblying the Quadrajet. Might be worth a quick watch.

 

[Bent77]

I think there is a good youtube vid on re-assemblying the Quadrajet. Might be worth a quick watch.

Its a holley

I'm a dummy on carbs, well know a little.. hah..

I thought the accel pump gasket is on the bottom and the bowl gasket goes around the bowl... so you don't need to do both at the same time?

Easier to pull the bowl to change the accel gasket. Then you can inspect both. Hate for you to pull the carb to do the aceel pump and not inspect the bowl gasket.

But if i were a betting man, I'd say accel pump

 

[RootBreaker]

True dat...

 

[RootBreaker]

well I took a stab at it. Replaced accel pump gasket and bowl gasket.. wasn't it.
ran back out and bought the metering block gasket.. guess what... not it..

so I took carb off (race shop I got parts from told me to bring it in) and when I looked under it, it was covered in fuel. I then hit the throttle holding carb and watched fuel pour out of the metering block. has like a plug in it and leaked all around it.

 

[RootBreaker]

ok holley wants the carb sent in even though I bought it april 22, 2016... has been sitting on my truck for some time.. hah...but since I haven't driven and when I did, didn't notice it... so they are going to have it shipped in and looked at.. go figure..

 

[Bent77]

Well that’s fun

 

[sweetk30]

sounds like they are going to make it right for you .

years ago my buddy went to trade school for auto mechanics . in the carb class he pulled his 4160 off the mopar 360 he had . it was close to new but figured learn on his own stuff . it ran good before and had no problems .

once he pulled it apart he found it had a huge casting chunk stuck in a circuit and was restricting flow on the 2ndary side .

once all cleaned checked out and re assembled no other mods other than remove the hunk of casting junk he re-installed it .

he took the car for a drive and said he had to 2foot the brake pedal to stop in time before the car was going to crash in to a pole . he had tested and tuned in the same spot before no problems.

this hunk of casting junk removed made the car a animal compared to before when he figured he was good . just goes to show you even a read to go out of the box unit might have problems.

 

[RootBreaker]

I just got an email and they are just going to send me a metering block.. easier and ill be up and running quicker

 

[Bent77]

I was kinda wondering why they’d want the whole thing


FYI, I always coated the gaskets with Vaseline . Then when you take the carb apart, the gaskets don’t stick

 

[RootBreaker]

I was kinda wondering why they’d want the whole thing


FYI, I always coated the gaskets with Vaseline . Then when you take the carb apart, the gaskets don’t stick

Never heard of that. Both sides slight coat?