Vacuum loss on Lorry

If I had to guess what the hole is at the line of lights it would have been the light for vacuum, the brakes were crappie to down right dangerous, I’ve since tried to bleed them and I lost a bit to much fluid , so I’m sad I didn’t take too much attention when information was handed to us.....

Back to the beginning then, top up the fluid and start b leeding again. Replace any of your vacuum hoses from the vacuum advance to the brake booster tank. These should be very easy to get, I bought mine at a car parts store, Bursons, locally and jsut 600mm cost around $10.00. So it worked out to be a cheap fix for me and one I am glad I have done. Lorry still has othe vacuum hoses of larger bore size and are moulded to shape so possibly will be genuine parts only with his age but so far so very good. Thing of tking Lorry for a run to Taree and back in the morning and pick up a 40kg load, just for fun too of course.

Rattail are you sure your power booster diaphragm isnt stuffed

John dunno about all jap trucks but Isuzu has a vacuum tank so like a ACCO you would have to fill that with brake fluid before made it back to the sump

Cobba , dunno if your truck has a non return valve in the vacuum line but most trucks with vacuum tanks do and they when working right will hold vacuum for weeks

Paul

Well I cannot tell ..... I’ve been on my own since my wife done a runner lol...... the cabin must be tilted because the canister sits on the inside at a 45’ angle too be straight, I thought I’d just get 2 newbies
The good old PBR VH44 from my young years on the hr Holden
I only bought one there are 2 , turns out they are VH99 about $500-$700 each , , so Paul I need to get the hydraulic circuits — as in hard pedal and then worry about the vacuum tanks

If you are getting a hard pedal,could be the slave piston stuck.....the PBR boosters only have alloy bores the slave piston runs in,and they do freeze up pretty quick when unused.....all the spares Ive got for the PBR boosters in the last 40 years have been rubbish made in Bangla Desh....the big diaphragm will tear in a year,the original Aussie one last teras and years......Ive got a better run out of a diaphragm salveged from a rusty booster than a new one from Repco.

Yeah no sorry I’ve confused you, I have nothing but spongy pedal I have no brakes at all now I have bleeding them, i tried to bleed them on my own and ran out of fluid
, I tried to bleed them on my own but ran out of fluid a couple of times..... the cabin must be in a 40 odd degree angle to get at the fluid canisters and it’s hard to do 3 jobs at once, I’ll have to bribe a mate so I need to get some pedal to check the vacuum!

I would get the hydraulic side of things working first
Then the booster and vacuum leaks etc

Paul

Hi Paul,
Yes Lorry has a valve of some sort between the vacuum pump and the first tank with a wire connected to it so this might be the valve you are thinking of.
What is the simple test again for leaking vacuum please, preferrably without flame in the open ?

RE: Hyd Brakes
brings back memories when a few of our trailers had Air over Hyd brakes when I first started learnin (stihl @ it)
When replacing hyd master cylinder
U fill the new master cylinder with brake fluid
and reach in to resevoir n tickle a lil valve @ the bottom of resevoir to start the brake fluid moving
then proceed to bleed the brakes starting @ the closest bleed nipple down the line
but this was many many moons ago on a singlr circuit
if the 1st bleed off is lower than the master cylinder u can open bleed n let it bleed o/night ... then proceed to next closest bleed nipple
cya

Yeah Paul if you read my last message that is exactly what I said, get some brakes and then worry about about vacuum