Adjusting Vacuum brake?

[Malcolm Towrie]

I posted a while back about a Canadian MkII carrier with low compression on 4 cylinders and poor running. The distributor rebuild fixed the poor running, but I didn't set up the vacuum brake adjustment. I left the adjuster backed off, intending to adjust it when the carrier was driven, based on listening for ping as per the Ford service manual.

Well I took it for a drive and I noticed two things. I couldn't hear any ping in first or second gear with the gas pedal to the floor. I'm not sure if that was because of engine noise. And the carrier struggled to pull second gear when turning in soft dry dirt. By struggling, I mean the engine pulled cleanly and smoothly, but rpm dropped with gas pedal on the floor, like I was in too high a gear. I should say I have never driven a carrier before and I have no idea what to expect.

I assume the engine labouring while turning in second gear is not normal? I suppose this is due to the low compression, but I'm wondering if some of it is due to over-advanced ignition timing since the vacuum brake isn't doing any retarding under load. How do you adjust the vacuum brake in a carrier?

Malcolm