Bleeding brake nightmare!

Afternoon All.

Me and my dad have owned this series 3 ex MOD 109 Ambulance for some years..



Its a great old tub... but it is testing my nerves now. It failed its last MOT on the two brake pipes from Master cylinder to Bias Valve in the chassis.

I set to, replacing said brake pipes (which came off easily enough due to the masses of underseal slapped on over the years). I struggled bleeding the brakes and ended up stripping everything down on the N/S/F to remove the bleed screw, size it to 10mm and try again.

My issue is, ive got every ounce of air out of the system possible. Pressure bled, force bled, replaced master cylinder and still.... I have a soft pedal. Ive even tried adjusting all the brakes.

First press of the pedal and it hits the floor, with small amount of braking force applied to the brakes. Once pressed again, the pedal is strong and sharp... untill released, and the cycle begins again.

I just cant seam to get rid of this issue!! Can anyone advise? Ive been "this close" to scrapping the whole thing... because its getting the better of me

It's fooked....tell ya what, I'll come and take it away

You know it makes sense

Twin leaders at the front with bleed screw at the bottom? If so bleed top cylinder first by cracking the unions or invert backing plate.

Snail adjustors have to be spot on to have any sort of pedal so worth rechecking

I see. It baffles me really. Theres a conventional bleed nipple at the bottom of the front drums.... yet there is a pipe going top to bottom. Usually bleed nipples are at the top (as air rises to the top)

So i need to bleed the fronts via the top union of said brake pipe? hmmm

Fun aint they[not]good mod is to run flex pipe to a bracket on the top of the swivel housing,then hard pipe to lower cylinder and back to top cylinder with the bleeder.Just running a flexi to the lower cylinder first is not a good idea.