C/30 rear wheels locked up, no fluid

[Stocker]

^ What they said. New is not too expensive, and anything that's been sitting -- especially dry! -- probably has corrosion. Even if not dry, the brake fluid can easily be contaminated, allowing corrosion to have done its evil work.

[phillip24fan]

Originally Posted by Stocker

Follow the brake lines to see where they go; it's possible the rear reservoir (your empty one) goes to the front brakes. That's how it is on my '72 K20 (with front discs). Not sure about your '70 C30.

I believe the rear diff is an Eaton, which on a C30 should be an HO72. Can you post a front view pic of it?

And where it sits now...


Is it better to put the photo bucket url link in like I've been doing or is there a better way to upload? the attachment button? My pictures seem to be too big

[Stocker]

Definitely an Eaton, most likely an HO72 since it's a 1-ton truck.

[swamp rat]

The HO52 and HO72 will look the same, there are a lot of opinions on how to tell which is which including the pinion preload bolt but most of the concensus leads to the size of the brake drums themselves as the determining factor.

Per your rear shoes, they are the rivited instead of bonded type, they can be re shoed if nessasary, Napa can do it.

Heres a couple threads for your reading pleasure.

http://67-72chevytrucks.com/vboard/s...d.php?t=200268

http://67-72chevytrucks.com/vboard/s...d.php?t=177514

http://67-72chevytrucks.com/vboard/s...d.php?t=595571

[Stocker]

Originally Posted by swamp rat

The HO52 and HO72 will look the same, there are a lot of opinions on how to tell which is which including the pinion preload bolt but most of the concensus leads to the size of the brake drums themselves as the determining factor.

Without reading through the threads you linked (good job BTW) I can add that HO52 came on C/K20s and some had the preload bolt while some did not. C30s had HO72 which always had a preload bolt.

[phillip24fan]

Dropped the drums off to be turned. $20/each at a local shop. Picking them up tomorrow. Planning to order everything on rockauto tomorrow as well. Been putting that off. The only thing I had trouble pulling off was the wheel cylinders. The bolts wanted to strip and it was a tight space to be in. I'll pull off the backing plates to make it easier.

Everything is dirty and rusty and I'd like to clean up/paint while I have everything apart. Do I need to use high temp paint on the drums? I was going to clean up the drums and backing plates with a wire wheel then prime (do I need to?) and spray with some black enamel. Rustoleum or whatever. Thoughts?

[phillip24fan]

It's been a while but I'm finally getting the brakes back together on my C30 to get it driving soon. I need a little help identifying some parts from the hardware kit to make sure I put everything together correctly.





Which of these springs do I use for the shoe hold-down and which pin (long or short)? The yellow springs are slightly taller. I received two of each total in the kit so I'm assuming each side of the axle gets one yellow and one silver.

[jocko]

Hey it's about time! Ha. Thanks for following up - I do the same thing, I wouldn't last long in a busy auto shop, I try to pretty everything up too much when I do it. It's a sickness. But a perfectly understandable one on your own truck. Probably should've mentioned before, but a few things are helpful when working on brake systems you aren't intimately familiar with. Digital camera is your best friend. Document everything before disassembly (I know, a little late for this great advice). And then, only disassemble one side at a time (except for the drums) - keep one assembled as the reference, keeping in mind that one side is not exactly the same as the other, it's a mirror image. Also keep in mind that you only need to replace what you take off - brake part kits can be somewhat generic and have more parts than you need. Clean what you can't replace. A parts washer, even a portable one is a huge help - but can also use brake cleaner spray. Have a good catch system to catch the drippings. Also, reference the factory manuals for the ground truth if you do not have a good ref to go on (or, actually, always reference them anyway, even if you do have an original truck). SSTim has a good link to them in this thread.

And, most importantly, do the rear wheels spin now?? You mentioned you were going to check now that the drums were off. I'm guessing they do - and that you just had one or two really, really stuck drums - considering that the lines were dry. Parking brake stuck? Interested to hear the cause of the original problem.

Would love to see a pic of this old truck and hear a little about it. Grandpa's old C30 - that sounds great, glad you're gonna get her moving again.

[phillip24fan]

Nothing fancy... He bought it about 10 years ago to use around our property. It's been parked the last few years which would explain the stuck brakes. The driveshaft spun easily so that shouldn't be an issue. It's had an engine swap to a 307 before he purchased it (don't know if that's a factory Chevy one); has a 4 speed. The bed has a hydraulic dump that is powered by a Chelsea PTO. There is a transfer case shifter on the floor for the PTO.

He had new rear tires put on right before he parked it. So they have excellent tread, no dry rot at all. Got those pressure washed and cleaned up.

My ultimate goal would be to put an 8 1/2' Longhorn bed on in place of the flat bed, like 72Freak did on a thread on here with his blue '68. I love the look of the dually tires tucked up under the bed. But it seems Longhorn beds aren't so easy to come by or affordable. I may think about taking an 8' long bed and extending it.

As for the brake job, I took a few pics on my cell phone for reference but I'm definitely wishing I had been more thorough, and only taken off one side. I planned to do it right away but got caught up with school and my memory has faded a bit since I disassembled everything. A 20 gallon stand alone parts washer is on my shopping list for the near future. I have PDFs of the overhaul manual and service manual for these trucks that have helped some.

Can't wait to get this thing on the road! Every morning there are a couple C10s at a local breakfast joint. Hoping to be able to roll up and join them. And I have been doing my own little lawn mowing/landscape business this summer to make money for college and it'll be cool to have this truck to use rather than my Grand Cherokee. It has tool boxes under the bed as well.