Thread: My Series III 88"

Originally Posted by goingbush

You mean the switch that goes on top of the pedal box ? thats the brake light switch. part no 575166 .

Theres a hole on the bottom of the booster , its for a vacuum warning switch on a diesel . blanked off on petrol models.

the 'genuine lucas' 575166 you get now are absolute crap , Britpart are probably better . I went through one every few months (daily driving) until I got sick of it and adapted a Nissan Navara reversing switch to the lucarse part, been faultless since.

Why is the vacuum warning switch only used on diesel, and not petrol ? I installed one from an old booster on my new booster, but it doesn't seem to do much, mind you I haven't tested it thoroughly and I have no idea if the switch is faulty or good.

Cheers,
John

Originally Posted by JohnboyLandy

Why is the vacuum warning switch only used on diesel, and not petrol ? I installed one from an old booster on my new booster, but it doesn't seem to do much, mind you I haven't tested it thoroughly and I have no idea if the switch is faulty or good.

Cheers,
John

I dont know, its a diesel thing I guess, Ive never seen one on any petrol 4x4 .
Had a few petrol inter trucks with them though.

If a petrol engine is running, it has vacuum - if a diesel engine is running and the drive to the vacuum pump is working and the pump is working, it has vacuum.

Those 'ands' are why diesels have a warning light more often than do petrol engines.

Should It be spring connected to these two holes (red circles on the photo)?

No. On 10" brakes there is a spring between the two shoes at the pivot end, but at the cylinder end there is only a spring between the leading shoe and an anchor on the back plate.

Originally Posted by JDNSW

If a petrol engine is running, it has vacuum - if a diesel engine is running and the drive to the vacuum pump is working and the pump is working, it has vacuum.

Those 'ands' are why diesels have a warning light more often than do petrol engines.

ok, so no harm having the warning light on my petrol 2.25 then ?

How do I test if it does anything, just pull the hose off the booster with the engine running ?

Thanks
John

Originally Posted by JohnboyLandy

ok, so no harm having the warning light on my petrol 2.25 then ?

How do I test if it does anything, just pull the hose off the booster with the engine running ?

Thanks
John

Just turn ign on, don't start it , push the brake pedal, that will use the remaining vacuum, light will come on.
A bit pointless really , As JD said, it the engine is running you have vacuum.

Originally Posted by JDNSW

No. On 10" brakes there is a spring between the two shoes at the pivot end, but at the cylinder end there is only a spring between the leading shoe and an anchor on the back plate.

Is that the same on LWB? No spring between the two shoes. Sorry I don’t know the brake size on SWB and LWB. It looks like I have lwb brake on mine. When I first order the cylinder the shop gave different type then I swapped as on picture. On the new cylinder it says LWB.

At the moment the wheel cylinder seems doesn’t retract back after The brake pressed. Does it mean the wheel cylinder need to be replaced?

Thanks