Bleeding rear brakes on 1978 C30 dually

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bee man

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hello I'm new to this site and am hoping someone can enlighten me on how to bleed my rear brakes.
I did a full tear down and replaced the wheel cylinder. I've got the brakes back on and installed the drum and need to bleed the brakes but they are so close to the leaf springs I don't know how to loosen or tighten the bleeder nipple. Does anyone have a trick or is there a tool I need?
 

fast 99

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These are what I used. Bleeder should be 5/16 or 8 mm. Sometimes a long combination will work. If tight will need a box end wrench.

top Matco SPW100 3/8 5/16
bottom Snap on B1458C 1/4 3/8
 

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bucket

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There are (or were) bleeder wrenches made specifically for that application. We had a thread about that several years back I think. I don't remember the manufacturer of the bleeder wrench I have.
 

Grit dog

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If the wheel cylinder is new, the bleeder isn’t rusted in so just use an open end wrench.
If there’s not room to get a box wrench over the end, that sucks but not until the next time 10 years from now when it’s rusted tight.
I generally put a bit of antiseize on bleeder screws…..for next time.
 

bucket

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It also matters if it's a cab & chassis rear axle. The brakes are REALLY close to the spring packs.
 

fast 99

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It also matters if it's a cab & chassis rear axle. The brakes are REALLY close to the spring packs.
Most of our trucks were cab and chassis. And yes, very tight. When replacing shoes, always check the bleeder before installing anything. Stuck or clogged bleeder usually means removing the wheel cylinder or at the very least unbolting backing plate for access. Plate can be pulled away from springs slightly with line attached for access. Stuck bleeder use 6 point socket.
 

bucket

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I was out in the garage and remembered about this bleeder wrench thing. Pictured here is my snap-on bleeder wrench that I use most often and also my specialty wrench that I can't remember the maker (red handle).

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And here I am trying to use both of them on my cab/chassis truck. Please note, I pictured the side with a broken and missing u-bolt... this pretty much doubles the access space, but I did it for picture clarity. The specialty bleeder wrench fits right in and would clear the u-bolt if it was still there. The regular bleeder wrench though, I couldn't even get it to engage the bleeder due to clearance issues all around. And it's even taking up the space that has been vacated by the u-bolt.

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I have no idea how y'all can manage to access that bleeder with a box end wrench or any type of standard bleeder wrench.
 

bee man

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C30 camper special 1 ton dually
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I was out in the garage and remembered about this bleeder wrench thing. Pictured here is my snap-on bleeder wrench that I use most often and also my specialty wrench that I can't remember the maker (red handle).

You must be registered for see images attach


And here I am trying to use both of them on my cab/chassis truck. Please note, I pictured the side with a broken and missing u-bolt... this pretty much doubles the access space, but I did it for picture clarity. The specialty bleeder wrench fits right in and would clear the u-bolt if it was still there. The regular bleeder wrench though, I couldn't even get it to engage the bleeder due to clearance issues all around. And it's even taking up the space that has been vacated by the u-bolt.

You must be registered for see images attach

You must be registered for see images attach


I have no idea how y'all can manage to access that bleeder with a box end wrench or any type of standard bleeder wrench.
 

bee man

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those are great photos
I've looked on line with and the wait for shipping is too far out. So I hope I can make my own

Would it be possible to get a picture showing the dimension of the offset looks like about 1 1/2"
 

bucket

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those are great photos
I've looked on line with and the wait for shipping is too far out. So I hope I can make my own

Would it be possible to get a picture showing the dimension of the offset looks like about 1 1/2"


Well crap, I forgot about this. Probably too late now, but here's some basic dimensions.

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bee man

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No this is perfect, been so busy with other things I have yet to try to build it. I really appreciate the time you took to get me the info.
 

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