D6D power brakes

Hi R.C.
The following test procedure may help--yes, it does cover the machines listed but, the D6D should be the same/similar--we used this at The Dealer for all later alike systems, but used the Service Manual pressure specs. for the particular later machine.
Sorry, the pages I have are photocopies handed out at a Cat Of Aust. Powershift Trans. Course I did in Oct. 1965.

Hope this helps.
Cheers,
Eddie B.

I will have to get some pressure testing gear then.

RC,
Maybe I missed it, but I didn't see the following info at a quick glance through the service manual: https://ch-part.com/i.caterpillar/smhs83540001/

Reckon if your linkage adjustments from lever to valve are all correct, then the control valve is the next step.

Most instructions for any work under the seat on the D4E, D5B, D6D start with '1. Remove Cab, 2. Remove Operater Station'

Thanks Glum, that is a good start to find the problem and I would suspect will fix it. It has been awhile, I hope you have upgraded from satellite internet by now. 😄

Yes, RC, its been a few years.
We have progressed a bit, but nothing happens fast in these parts😊
That D6 with aircon looks like a nice upgrade from the old D4D.

Yes I do not miss this one bit.

[attachment=59061]20200511_130249.jpg[/attachment]

I ended up getting the brakes repaired. The problem was in the steering control unit. The info Glum linked to was not applicable to my dozer, it is for the newer series of steering control unit. Mine has an older one and the cams that push the spool valves were plain worn out. Some new ones installed and the steering is how it all should be.