Weak PACBRAKE on 1995 12.7 S60

My mechanic was doing some head work 18 months back, and , in a classic 'Since you is in there' moment, I told him to rebuild the engine brakes. Brakes then performed worse than prior to touching them.

He admitted that he could not 'set the clearance' correctly, and had ground a chamfer off the bottom of the plungers, and maybe this was the problem. So he removed the PACBRAKE set and installed a Jacobs set until he could source new plungers.

Jacobs were substantially noisier, and weaker than the untouched PACBRAKE. Plungers proved difficult to source, PACBRAKE told me they no longer have parts for that set, mechanic sourced some from E-bay that were the same 3/4" OD. The original 12 consisted of 6 that had an oil orifice, and 6 that were solid - he had a machine shop plug the orifices on 6, to get back to square one.

Re-installed yesterday, I test ran it - weaker than ever. All 3 stages function, but are very quiet, and fail to retard speed even bobtail. The Jacobs that were in there had begun to throw CEL and cut between Stage 2 and 3 erratically.

He said the setting was to wind the screw down then back off a half turn, for .025" clearance, but was concerned that all he could get on 2 of them was .023. No popping going down the road when I drove it.

I'm puzzled, because he's not a shade tree mechanic by any means - but has royally messed up the engine brakes somehow. To his credit he hasn't charged me a dime with this issue -

Is anybody here very familiar with PACBRAKE's - I'd REAAAAAALY appreciate some input, perhaps a call to my mechanic.

Forgive me for not having the specific housing numbers , I had them somewhere when I was looking for plungers.

6067GK60 is the engine model. VIN SD370536. 1995 379 Pete.

 

All good - before they were messed with - I could control 75K+ down 5% grades by selecting the right gear and toggling between stages.

I know they can do better.

@pushbroom @OLDSKOOLERnWV @Goodysnap too.

 

I’ll ask.

Edit - asked and waiting.