Vacuum loss on Lorry

Not so long ago Lorry started to not want to hold vacuum for short periods of time like when you fuel up and start up you had to wait a while. At that point I went around the vacuum hoses and measured up how much hose I would need to buy of what I thought was 10mm bore but ended up that 9mm bore was perfect. I also asked about the vacumm pumps just in case but the other day I used 600mm of the 9mm bore hose and bought all new hose clamps and replaced the straight pieces from pump to chassis, chassis to a low valve I think then both strtaight hoses going to the tanks.
Good news is that now from standing overnight to when the warning light goes out is around 20 seconds and after about 10 minutes it took around 12 - 15 seconds to switch the warning light off. Very happy with the outcome.
Thanks to all who replied with different types of pumps available and ideas.

From the old railway era. The test for vacuum pipe leaks is to hold a flame (eg candle or gas lighter) at the suspect joint. The flame will be sucked into the joint where there is a leak.

I'd be worried about catching fire on Lorry, but a good way to test. As it has worked out it appears all good now.

Hey cobba I think you’re truck is a diesel yeah? Just wondering where or what type of equipment do you have (what ever) that supplies your lorry of vacuum now , factory or aftermarket equipment , thanks Jim

Yep Lorry is a FC144 Fleeter (I think) Hino with factory vacuum pump on the original alternator. Just the simple small pummp that bolts to the back of the alternator. NOw the vacuum leaks appear to be gone that small pump at idle sucks the air out of 2 vacuum tanks about 300 diameter round and 450 long in under 20 seconds. Before it seemed to take forev er but that was realistically around a minuite. I get excited when it's time to take Lorry anywhere so anxious to get going.
If needed I can take a pic of it tomorrow if needed.

Yeah cool mate , I’ve got lots of hoses to check out and might do as you did, no sense buying a alternator , I just remembered that this truck doesn’t have an alternator/ vacuum pump, and because it’s got a 345 petrol so it has 2 hoses and pipes running from the engine to the vacuum tanks at the back chassis, plus all the little lines running around the inlet manifold for the pollution hoses , It’s hard to start when it’s cold, I’ve ordered a carby kit but lack of vacuum wouldn’t help at all ....

Im no carby expert at all
But I think when you pull the choke out it creates heaps of vacuum

I could and most probably am wrong

Paul

Yeah I might replace the engine hose s I guess it’s the little ones that the heat, at the moment anything vacuum related is all coming out of the engine including advance on the timing advancing or not , I will probably get a vacuum/boost gauge and then I won’t be paranoid, ahh ha , Jim

You can pump in straight petrol by simply working the pedal two or three times,depending on how cold it is....The V8s crank pretty slow,and sometimes take a while to get fuel up to the carb,if they been unused.....All the Inters I had have got a red light on the dash for vacuum....Sure sign of vacuum leaks is idling too fast that cant be slowed down......You can also save a lot of fuel by idling with a weak mixture,cause this is sucked in on a downhill with closed throttle.

With vacuum boosted brakes ,you should have a vacuum tank too,so if the booster leaks fluid ,it doesnt go straight into the engine.In a Jap truck with a exhauster on the alternator,the fluid goes into the engine oil,and does the same kind of damage as antifreeze leakage.