Brakes without servo assistance.

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neilly

neilly

Well-Known Member
Posts
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Location
Oxfordshireness
So, driving home from the weekend it felt like the brakes required a bit of extra oomph to get the 90 300tdi to stop.

Having a look this morning, tried the pedal / servo test and it appears I no longer have servo assistance, joy oh joy.

Pulled the vac pump pipe to the one way valve and I have vac there, it sticks to my thumb, not strongly but sticks. pulled the one way valve and I can blow through one way but not the other.

Took a turbo / vacuum gauge and connected it to the vac pipe and have 20 in hg at the servo side of the one way valve. Looked in rave and cannot find a given figure for the vac pump. Anyoone know what the if there is one a given vac should be ? I will probably go and check the td5 D2 to see what that has as a reference.

But having no assistance at all , time to start looking for a new servo. now to find out if this is one of the original 1987 pieces or a bitsa piece.

Cheers
 
So further on,

If I start it I have no servo assistance, If I leave it a few minutes it gets slightly better, If I pull the one way valve after 15 secs of stopping the engine I have a very slight inrush of air , but not a lot. If I leave it a little longer 30 secs, there is nothing when the one way valve is pulled. Now in comparison, the D2 Td5, has approx 25 in hg of vacuum at the one way valve, after stopping for two minutes and pulling the one way valve the in rush of air is much more noticeable.

Looks like a new servo is on the books.

Guess it was one of the bitsa bits on it, label states Lucas SJB101891, now to find a replacement.

Cheers
 
Last edited:
Bit of a faff but what about parking both cars close together and using some hose connect the d2 vac pump to the 90s servo just to confirm its the servo at fault and not the pump, might save you some money and hassle?
Im sure Ive read a few posts over the years where people have replaced the 300 vac pump and can remember my mate doing the same on a friends 90.
 
300 vac pumps are always going, the one on my donor engineeas no good, chucked a new one on and me brakes were back like to before with the old engine
 
My vacuum pump went recently. I knew it had gone because there was a big puddle of oil under the defender. One of the small 'core' plugs had come out. I managed to tap it back in and that stopped the oil pouring out but some of the rivets holding the end plate on were slack, so I changed it once the new one arrived. But I didn't notice a change in braking, so maybe the vacuum was still working.
 
Yahoo,

It is nice to have brakes again, not the vacuum pump as mentioned / suggested above by others . As per my investigation in the posts above, I purchased a new Brake servo from Maltings / Isle land rovers on Ebay ( Fantastic service, ordered by 1PM delivered by 11AM the next day and cheapest by far:D:D:D............Result)

Cheers
 
chris-the-gerbil said:
20 inch of vacuum is a third of atmospheric
Click to expand...

Really? I thought it was more than that when I looked at this in the beginning of the week. iirc -1 bar is approx 30 in hg. Maybe I looked at the wrong thing. Only ever used vaccum before for robot suction cups and lifting .

Cheers
 
Last edited:
raywin said:
checked mine some time ago it showed .27bar
https://www.landyzone.co.uk/land-rover/td5-brakes.304739/
Click to expand...

I would not guarantee the vac / turbo gauge is correct, only one I had in the garage. Worked as a comparison to show what the D2 and the Fender have from the vac pump when tested back to back. Was the reason I asked in the first post if anyone knew what the vac should be. Your 0.27 Bar may well be correct.

Cheers
 
neilly said:
I would not guarantee the vac / turbo gauge is correct, only one I had in the garage. Worked as a comparison to show what the D2 and the Fender have from the vac pump when tested back to back. Was the reason I asked in the first post if anyone knew what the vac should be. Your 0.27 Bar may well be correct.

Cheers
Click to expand...
Hi Neilly
I actually used a Druck electronic pressure gauge which I have calibrated for my work, so I was pretty confident it was OK.
 
raywin said:
Hi Neilly
I actually used a Druck electronic pressure gauge which I have calibrated for my work, so I was pretty confident it was OK.
Click to expand...

Sounds good, as I say, mine may well have been reading wrong, just used as a comparison for what I needed. Guarantee it is wrong now as I dropped it and the needle now points to 10 in hg when not attached to any pressure / vacuum. LOL.

Cheers
 
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