72 c10 brake booster replace

[pbzzz]

I need to replace the power brake booster on my all original 72 c10 350/350 .
I do not have factory service manual . Does anybody have description from fac svc manual as to what to do after master cylinder is removed ?? Tnx in advance

[roboticjunky]

Here are the factory service manuals.

https://67-72chevytrucks.com/vboard/...d.php?t=558016

[pbzzz]

Thanks . . . Not wanting to do all the downloading, etc. You are right, I need to buy hard copies . Was just wanting a few "lines" from "remove brake booster " .

[roboticjunky]

Removal from Vehicle
1. Disconnect the brake lines from the two master cylinder
hydraulic outlets. Cover brake line fittings to prevent
dust and dirt from entering brake lines.
2. Disconnect the vacuum hose from the vacuum check
valve on the front housing of the power head. Plug
vacuum hose to prevent dust and dirt from entering
hose.
3. Disconnect the power brake push rod from the brake
pedal.
4. Remove the four nuts (inside vehicle) from the mounting
studs that hold the power brake to the dash.
5. Carry the power brake to a clean work area and clean
the exterior of the power brake prior to disassembly.

[Ironangel]

There really isn't anything in detail explaining the removal of the "booster" in the manual other than what Roboticjunkie posted. My 72 manual reads the same however, I changed out the booster in my 72 C/10 without removing the studs in the dash. Just disconnect the four nuts on the back of the booster and the vacuum line and its off ready to "exchange" for a new booster. I think there are two options for boosters so take your booster with you to the parts store. Leave the bracket and push rod in place on the firewall. No need to do anything under the dash. Also, do not attempt to dismantle the booster because it has a spring in there that can ruin your day if you open it up. Brake fluid often leaks from the master cylinder right into the booster causing the booster to eventually fail. It's been a few years so I'm not sure about the push rod at the firewall. There is a clevis there that may need to be disconnected, I cant remember. That push rod may need to be adjusted so that 1/8" inch of free pedal travel is maintained.

[pbzzz]

Thanks to both Robot and Iron . Iron . . . that pin/clevis/clip at the back of the
rod coming out of back of the booster is my real concern .

It looks like it would be easy to drop the retaining clip (lost forever) and possibly difficult to pull the pin out . . . and reinstall . It's near firewall / way in back .

I am an old tart (75 yrs next week) with 10 month old lower back fusion . I have done my own work for over 60 years now . Was thinking might be easier on my body to remove booster (bracket and all) but instead of the 4 nuts/bolts on inside of cab as manual reads I am seeing 6 nuts holding booster bracket under hood on firewall .

Prefer NOT to pay somebody to do this work, but maybe it's time . . .

Thanks again to you BOTH for your info . pb

[cherokeejohn]

hey pbzzz, i did this to my 72 C/10 w/fact pwr disc brakes a few years back also.as stated above, there is 2 diff types of boosters on the 72s. there's a 11" ( this is what mine has) and There's a smaller one, either 8 or 9 inch so take a measurement of yours first off. i did mine on my kitchen counter top without a hard copy manual, i did however download the files posted above and look at them on my phone while working. i highly recommend doing the master cyl and prop valve at the same time. when i did mine, immediately following the booster my master went out on the test drive and then the prop valve in less than 10 miles after the master. so i ended up replacing all the components individually. i later discovered a full set-up already assembled, bench bled , and ready to bolt on for about $50 cheaper than i had spent. although originally i intended to replace only the 1 part, the booster, with the rest of the components being 40+ years old, the others were so wore out that when the new part was added in, the next down the line couldn't hold up to the pressure . Just some qwik advise.i seen the complete set up on a site called (pirate4x4 in Asheville,NC), but i believe that LMC,Classic,etc..all have it the same now too. As for the job itself, I'm disabled with only 25% use of my left arm and damaged wrists as well and it wasn't bad, took a few hours the 1st time around, after all the rest well i can prob do it as fast as a nascar pit crew, lol Hope this helps a little. i hate to see another suffer from the same things i once did myself. And the PDF files posted above are worth downloading, either way you'll have something to reference toonow and in the future.

[pbzzz]

CJ . . . Thanks so much for your info . I just replaced master cylinder a week ago, so things should??? work well ??. I now have the info I need to proceed with the fix . Thanks again to you , and previous reply(ers) . This is a great chevy pickup website .