76 d700

7

70chall440

Active member
Thanks Ron. I don't have a 3/4" impact (or a 1" for that matter). I think I will just use my torque multiplier and keep an eye on them. It isn't like I am going to be driving this truck daily, so I think if I get them reasonably tight it should be ok. I just have to get past this brake issue.
 
7

70chall440

Active member
Sorry it has been awhile since I posted anything on this. I haven't had a lot of time to work on it lately due to work, however I got some things done yesterday and today and believe I got it sorted out. As I went through on here previously, I have replaced the 4 front wheel cylinders which did yield some positive results but there were still issues with the front brakes locking up. I then focused on the brake booster system. I ordered 1 new one which turned out to be the wrong type ($200 gone); I decided to disassemble and clean the booster which services the front brakes. I removed the booster and took it apart; it was pretty grungy with rust/dirt/brake fluid but nothing super bad. There is a valve in the front of the cylinder which seems like a residual pressure valve or something close; it has a rubber base, spring and cap all held in by a small wire snap ring. I disassembled it, cleaned and when I went to reassemble it the snap ring decided it was time to depart and shot off into the unknown. After an hour of looking I went to Napa and bought some normal snap rings (2 trips to get it right); but as they say persistence pays off and I got it all back together. When I had removed it, the feed line was leaking from the MC which I expected and caught with a pan. After I got the booster back together I reinstalled it. I then went to add some new brake fluid and bleed the booster; it was then I noticed that the booster I was working on was actually for the rear brakes... :pullinghair: so out came the "other" booster and got to practice my brake booster rebuilding skills. Got that one back together and reinstalled. I then bled them both and it was time for a test. Started the truck up (that 360 runs really well), put the truck into reverse, the truck moved and I hit the brakes, they grabbed as always (very grabby); release the pedal and VIOLA it moved. They did grab/lock once, but I moved forward and they released. I then took it down the road to see; that's when I found out that the very large hood was not latched.... I was going slow so I stopped and closed it. Continued down the road without issue, then turned around and came back w/o issue. Actually the brakes seemed to get better as I went. I still need to tighten the lug nuts and reinstall the gas tank support (bar that runs between the 2 tanks). So, for the most part I think I am past this (finally).
IMG_2540.JPGIMG_2548.JPGIMG_2549.JPG
 
R

RonG

Well-known member
I gloat over a successful repair like that especially after you have so much invested.I have a snap ring set that I bought a few years ago and it is nice to be able to just grab another one when that happens.I am happy now too.Ron G
 
7

70chall440

Active member
Yea I am pretty happy about it. A snap ring set is definitely in my future; buying them one at a time sucks. Not something you use all that often but when you need one, well... you need one and unfortunately it is "that one"; not many options other than sourcing one.

Now I have to figure out what I am going to do with this rig. I still harbor thoughts of making a car hauler out of it but I either have to make a tilt bed and/or lower it. Lowering it is definitely harder than the tilt bed, but I have to obtain all the hydraulic to make it tilt as well as build a hinge point and extend the back of the bed about 4'. In realty, the rear axle needs to be about 2' further back to make it more accepting of a variety of vehicles but as it stands it would take most w/o issue I think (with the 4' extension). Definitely not something in my expertise, but I am sure I will figure it out.
 
R

RonG

Well-known member
I have to admit that the snap ring set was an offshore product but it is nice when you need it.I keep my old Dodges and when I bought my '83 I called my BIL and they came down from Maine to get my '75 and took is back to haul their stock car with.I had the sides of the bed drawn together with a comealong which I never got back.lol.I still have my '83,I think my '95 is rusted worse than the '83 is.That Dodge of yours looks pretty nice.Let us see what it ends up looking like when you are finished with it.I loved the looks of that Bighorn,too bad they quit making them.Ron G
 
7

70chall440

Active member
Still trying to figure out how to make a car hauler our of it. What model was your 75?

They still make the Bighorn; mine is a 14 2500.
 
7

70chall440

Active member
Wasn't aware there was a Big Horn truck until right now.. :)

I am not a "truck" guy per se but I am finding that I have a lot these days.
 
7

70chall440

Active member
Well it is official I am stupid... So I was pulling the D700 out of the shop yesterday and bigger than crap the brakes were dragging like before, but it seemed to be kind of working and I needed it out so I basically pushed through it and in about 10 minutes it began to work as it should and I got it to where it needed to be and parked it. As I sat there thinking about it the proverbial clue like flashed on; I remembered that many big truck require the air pressure to build up in order for the brakes to work properly. Most big trucks have a buzzer that sounds until the pressure is achieved signaling the driver that it is ok to begin driving; this truck had a buzzer that wasn't hooked up but seemed to be wired to the trans temp. I "thought" this was someone's idea of a high temp warning when in fact I know believe it was originally hooked up to the air pressure sensor. Oh well, the brakes needed some attention anyway (yes that is me justifying my efforts...)
 
Steve Frazier

Steve Frazier

Founder
Staff member
I'd be concerned if it's taking 10 minutes for the truck to build air pressure, something's not right with that.

The reason big trucks need air pressure to move is there are spring loaded "Maxi" brakes that must be defeated by air pressure, these slam into place generally when the air pressure drops to 60psi or below as a safety measure. I'm not sure the system you've described in this thread would have them.
 
R

RonG

Well-known member
Here is one of the reasons they invented spring brakes.0814f.jpgI wanted to add another pic but I am being blocked,sorry.Ron G
 
Steve Frazier

Steve Frazier

Founder
Staff member
I didn't mention they are on the rear axle, not the front. There are two air chambers stacked one atop the other.
 
7

70chall440

Active member
My truck is different that that, there is an air tank on the left side that goes to the boosters. It "seems" like the entire system has to be "charged" or reach a point of either vacuum or air for the brakes to function properly. I need to do some more research on it. The truck is out of the shop behind my barn currently and it is raining a lot, so it might be awhile before I can really dig into it. I will look at the FSM and see what is in there.
 
Steve Frazier

Steve Frazier

Founder
Staff member
Yes, your system is definitely different. I'm familiar with both hydraulic and air brakes, but I've never seen an air over hydraulic system, only heard of them.
 
7

70chall440

Active member
I am not sure what is going on there, the only thing I can find remotely close to this issue is a system called the "Super Fail Safe Spring Powered Brake Actuator (Rockwell)" however this appears to run off of air pressure and I do not believe this is what I have going on. It "appears" to have a vacuum line running to this tank, but only one going in from what I can see. I need to crawl under it when it dries up and see what is what.
 
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