Speedibleed and GMT400

[D60]

I've got the C200 adapter from Speedibleed, but in thinking about it I have some reservations.

Specifically, you're going to start with air in those two blue tubes. You can't really purge it without a check valve at the end of each tube OR you could try to leave it flowing as you cram it down into the reservoir, which would be a nightmare.

Then, unlike other adapters that fill your fluid reservoir from the top of the reserve fluid, you're cramming whatever is in the tubes directly into the master at the bottom of reserve fluid.

This seems like a good way to potentially introduce air into the master? How is this any different than letting the reservoir briefly run dry?

I'm not saying I'm correct. And maybe my small brain is oversimplifying?

I used this today on a '98 and results were terrible, but I can't yet say the adapter is to blame-- it could be a dozen other things including mekanik stupidity.

I'm open to discussion.
@Trav

 

[jhellwig]

The brakes on those models are mushy suck at best. Even on the ones with 4ish wheel abs and hyroboost. You aren't going to ever make it great.

 

[D60]

Yeah that's what I'm finding.

I did take the master off and bench bleed it again and then bled at the master once installed by cracking the fittings. It's better, but still sucks.

This one is vacuum, JB7 I think

 

[clinebarger]

Think I saw where you put new brake shoes on some oversize drums? Until the brake shoes size themselves to the brake drums it's going to be spongy....Worse than the normal spongy GMT400 pedal.

 

[D60]

Think I saw where you put new brake shoes on some oversize drums? Until the brake shoes size themselves to the brake drums it's going to be spongy....Worse than the normal spongy GMT400 pedal.

New shoes and the larger wheel cylinders. I did consider what the larger cylinders might do to pedal feel but anecdotally everything I saw just said the cylinders made for somewhat stronger brakes.

I wasn't expecting miracles just hoping for any improvement.

On the Speedibleed, I guess I should submerge it then purge it, then clamp it into place!

 

[ls1mike]

The brakes on those models are mushy suck at best. Even on the ones with 4ish wheel abs and hyroboost. You aren't going to ever make it great.

Agreed. my kids old GMT 400 had horrible brakes. We replaced the rubber lines, the calipers, wheel cylinders and master. It was a slight improvement. We had order some upgraded stuff to put on it, but then he wrecked it...

 

[clinebarger]

We used to grind/Re-Arch brake shoes to fit the drums & the results were night & day different. It can take quite a long time for 13" shoes to size themselves.

I would have the reservoir a little low, Then purge the air out of the adaptor....Gives the purged fluid somewhere to go.
Never really needed to pressure bleed a GMT400.....Unlike late model Impala's that almost require it.

 

[4WD]

Oddly we have a Goodyear service center next to Napa and they knew the combo to put on my old GMC …
I really could tell in driving and the parking brake used to front launch my boat on my really steep ramp …

 

[clinebarger]

Oddly we have a Goodyear service center next to Napa and they knew the combo to put on my old GMC …
I really could tell in driving and the parking brake used to front launch my boat on my really steep ramp …

Like I said, When the shoe fits the drum well.....It's all good. I drove a 1969 C10 for years with drums all around, ill fitting shoes would make that thing a death trap.