404 Braking system

dave404 · Posted: Sat Jul 03, 2010 6:42 am Post subject: 404 Braking system

Hi, I've just replumbed the braking system on my Unimog 404 (standard single line circuit). I have no leaks in the system and have rebuilt 3 of the wheel cylinders and replaced 1. The master cylinder has also been rebuilt. When bleeding the system, I have used a pressure type bleeder and when going around the circuit, I have bled the lines but I guess there must still be some air in the system somewhere. Does the master cylinder have to be purged first or last when bleeding?

mike97 · Guest

Hi Dave,
Its best to bleed at the master cylinder first and then bleed at the wheel cylinders. Ive allways bled the system with out the need for a pressure bleeder, just craked open a nipple on wheel cylinder one at a time and a couple of pushes on the pedal each time.
Have you got a spongy pedal or just too much travel, have you checked that the shoes are adjusted up correctly?

regards Mike

dave404 · Posted: Sun Jul 04, 2010 9:16 am Post subject:

Hi Mike, thanks for the reply. I'd say they are just spongey. Each wheel was adjusted by turning the two scrolls, inturn, until the wheel locked up, then backed off just enough to free the wheel. I did a test on the brakes by driving along then applying the brakes with the clutch out. Normally the engine would stall, but in this case the engine continued running and the nearside rear wheel was doing a burnout on my drive!!
On a more postive note, I've got my PTO and crawler box fitted and my Nissan 6 pot diesel in and running a treat. Exhaust is through a 3" stainless pipe with no silencer, it sounds awesome when the turbo spools up!!
Thanks, Dave.