K5 almost killed me brakes to the floor

[BryanS]

New to me 82 k5

Brakes went to the floor and stayed there. Tried lifting pedal with my foot to pump them….nothing

I just happened to not wreck and was able to get back to my driveway. Pretty lucky because I was about to beat on the truck to see how she ran after playing g with the carb.

Don’t know the history of the truck but pulled the MC cover and the fluid is black like oil.

I was going to do the MC and Probally the booster ( because it’s ugly and suspicious)
What parts should I use? Are there any upgraded MCs that will not break the bank or be hard to instal?

 

[Ricko1966]

New to me 82 k5

Brakes went to the floor and stayed there. Tried lifting pedal with my foot to pump them….nothing

I just happened to not wreck and was able to get back to my driveway. Pretty lucky because I was about to beat on the truck to see how she ran after playing g with the carb.

Don’t know the history of the truck but pulled the MC cover and the fluid is black like oil.

I was going to do the MC and Probally the booster ( because it’s ugly and suspicious)
What parts should I use? Are there any upgraded MCs that will not break the bank or be hard to instal?

Booster won't make the pedal go to the floor,and I'd trust a used factory booster over a new aftermarket booster. As for making the pedal go to the floor,was the master full of fluid when you checked it?. If so I'd say the master is probablybypassing( not an uncommon problem) New master and bleed the brakes is the most likely fix. I am assuming the pedal pushrod is in place and connected.

 

[BryanS]

Booster won't make the pedal go to the floor,and I'd trust a used factory booster over a new aftermarket booster. As for making the pedal go to the floor,was the master full of fluid when you checked it?. If so I'd say the master is probablybypassing( not an uncommon problem) New master and bleed the brakes is the most likely fix. I am assuming the pedal pushrod is in place and connected.

Thank you for the quick response!

Yes master was full. I know the booster will not make pedal soft but I thought if I had the master off now would be the time for the booster. That said I would much rather have an ugly booster that works than a pretty one that does not

Stupid question… how do I check the pedal pushrod.

What MC should I get Acdelco?

I have been out of this scene for 30 years and very rusty

 

[Ricko1966]

Thank you for the quick response!

Yes master was full. I know the booster will not make pedal soft but I thought if I had the master off now would be the time for the booster. That said I would much rather have an ugly booster that works than a pretty one that does not

Stupid question… how do I check the pedal pushrod.

What MC should I get Acdelco?

I have been out of this scene for 30 years and very rusty

Stick your head under the dash and .ake sure there is a pushrod pinned to the pedal and going into the booster. Only reason I said anything about it,is your head line says New to you,making sure previous owner hadn't disconnected it for who knows what reason,and hadn't reconnected it. As for master cylinder brand I cannot tell you, I will tell you AC delco,now has three tiers. So cheap AC Delco is now the same offshore crap as all the other offshore crap. I try to pick name brand stuff in middle or upper price tier generally. I've had good luck with A1 Cardone, I used to not use rebuilt Masters,but now all the new ones are chineese.

 

[ali_c20]

If that would have happened to me I would check every single part of the brake system and replace everything that looks not 100% ok.

I never had any issues with Acdelco Gold and Raybestos Element3.

Is the work on remanufactured parts done in the US or are they shipped to Mexico, China, India or God knows where to be rebuild?

 

[Grit dog]

Assuming it was not the first time you pushed the brake pedal, ie it had brakes when you started driving it, or yesterday or whenever.
Sudden brake loss and no leaks as you described is almost certainly the master cylinder.
And not a big deal to do the booster later. It’s only 2 easy to get to bolts. You don’t have to disconnect the brake lines or bleed the brakes if replacing the brake booster.

 

[Grit dog]

Nice looking blazer btw!

 

[BryanS]

Stick your head under the dash and .ake sure there is a pushrod pinned to the pedal and going into the booster. Only reason I said anything about it,is your head line says New to you,making sure previous owner hadn't disconnected it for who knows what reason,and hadn't reconnected it. As for master cylinder brand I cannot tell you, I will tell you AC delco,now has three tiers. So cheap AC Delco is now the same offshore crap as all the other offshore crap. I try to pick name brand stuff in middle or upper price tier generally. I've had good luck with A1 Cardone, I used to not use rebuilt Masters,but now all the new ones are chineese.

Awesome thank you
I’ve had the truck for about 2 weeks and the pedal is attached

 

[BryanS]

Assuming it was not the first time you pushed the brake pedal, ie it had brakes when you started driving it, or yesterday or whenever.
Sudden brake loss and no leaks as you described is almost certainly the master cylinder.
And not a big deal to do the booster later. It’s only 2 easy to get to bolts. You don’t have to disconnect the brake lines or bleed the brakes if replacing the brake booster.

Truck drove from Alabama to FL 2 weeks ago. Lost the radiator along the way but otherwise went well. I’m going to go piece by piece and do the lines, calipers, drums, parking brake….maybe rig an anchor I can deploy in emergencies

 

[SquareRoot]

Great time for an LS swap. Wont fix the brake issue but it will make you not care about it anymore.

 

[Grit dog]

Truck drove from Alabama to FL 2 weeks ago. Lost the radiator along the way but otherwise went well. I’m going to go piece by piece and do the lines, calipers, drums, parking brake….maybe rig an anchor I can deploy in emergencies

Ok that’s great. Probably needs that stuff. Maybe.
Been a bunch of posts like this this week where the person wants to shotgun parts at a problem. That’s fine but fix the problem first. Then go nuts upgrading parts.

Y