Reggaerover
Member
True! I found a used brake booster for €70 so that’s worth a try. If that doesn’t work I’ll look for a vacuum gauge to test the vacuum circuit.
Reggaerover
Member
Might be worth looking for a good used one at that price...
a bit cheaper at paddocks:-
https://www.paddockspares.com/sjg500020-brake-servo-rhd-from-3a000000.html
But then I realise yours might be LHD ?
My D2 is indeed LHD luckily I found a used one for €70 so that’s worth a try! Thanks tho!Might be worth looking for a good used one at that price
a bit cheaper at paddocks:-
https://www.paddockspares.com/sjg500020-brake-servo-rhd-from-3a000000.html
But then I realise yours might be LHD ?
Reggaerover
Member
So today I replaced the booster and it did not make a difference so i followed the vacuum hose again and shortly after the vacuum pump there is a T-piece (see picture) that has 2 realy small vacuum hoses go to a sort of air valve (see picture) do you know what use these have ? Is it smart to just go buy a air hose of the same diameter and replace the hole vacuum hose ? Thanks in advance
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Landmark2
Well-Known Member
I think these are to do with the EGR system, I've seen mention of bungging some of these pipes up when people remove or blank the EGR off
Check here http://new.lrcat.com/#!/1232/38332/38333/2950
Griff
Check here http://new.lrcat.com/#!/1232/38332/38333/2950
Griff
Reggaerover
Member
So if there is a problem that will effect my brake vacuum to ?
Reggaerover
Member
As you can see on this picture there are 2 hoses cut off and strapped double together, do you think it could leak from here ?
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Reggaerover
Member
So I replaced the vacuum hose to and it is without succes. I’m out of ideas. The vacuum pump is new to so is it possible the vacuum system is ok and the problem is somewhere else ?
Hi, I replaced my power steering pump with one of those £100 chinese ones & it didn't last more than fifty miles before the steering had no assistance. So it could be the vacuum pump has failed on your new alternator, what make of alternator did you buy & have you still got your old alternator so you can swap the vacuum pump over ?
Reggaerover
Member
I don’t know, I had let it done by a Land Rover specialist because I didn’t know how hard it was to swap an alternator. He ordered one so maybe I will call him tomorrow to hear what he thinks. Alltough I had that brake problem from the beginning when I bought it but only when going in reverse. So alternator got changed after and didn’t make difference
Reggaerover
Member
True, what should be a good measurement that should come out of the gauge ? Never used one before so don’t know what to expectSorry to harp on, but ^^^ ....
A gauge will tell you what is going on....
Have a nosy here:-
https://www.knowyourparts.com/techn...-brake-components/vacuum-booster-diagnostics/
If you search around the web, you'll find that the figures given are pretty much standard, across the board - 15-20 inHg ....
But, the actual reading is less important that checking for leaks.... which, from your posts above, it appears you have ....
Reggaerover
Member
So my vacuum tester arrived and I measured 24inHg when standing still. When I push the brake pedal the first time it dropped to 10inHg and all the pushed next it dropped till 5inHg. After a couple seconds it goes to +/- 24inHg again without brake pushed in. I also tested when sitting on 24inHg to move the hose on all the connecting points and it never dropped lower then that. Do you known something more now ? I can’t figure it out haha. I also tested pushing the gas to 1000rpm and then it went to 30inHg. What I also tested is a straight hose from vacuum pump to brake booster to bypass the 2 air valves. Didn’t do anything to so don’t think the leak is there.Have a nosy here:-
https://www.knowyourparts.com/techn...-brake-components/vacuum-booster-diagnostics/
If you search around the web, you'll find that the figures given are pretty much standard, across the board - 15-20 inHg ....
But, the actual reading is less important that checking for leaks.... which, from your posts above, it appears you have ....
I hope you can help me out.
Thanks in advance.
Reggaerover
Member
Oh wait I think I might be wrong here. I didn’t read the tester right I think. This is a picture when engine is running. I think this will give the answer to my problem… instead of 25inHg it reads 25 cmHg. Which means only 10 inHg. Vacuum pump not good then ?
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Pawl
Well-Known Member
The vacuum value is definitely very low - either because the pump is no good or because of leaks.
In an earlier post someone said the vacuum should be between 15~20 in Hg.
Actually, for a diesel engine or any engine with a separate vacuum pump, the value should be quite a lot higher - typically 25~30 in Hg.
You made a comment in a previous comment that the brake pedal would sink faster after the engine started with the original alternator.
I think this suggests your original vacuum pump was much better for vacuum & probably throughput.
There are 2 important performance features of the pump :
1 - Maximum vacuum level - eg 30in Hg
2 - Throughput - ie how fast it can generate maximum vacuum level from a lower level.
"Throughput" is very important because it effects how good the brakes are if you have to make repeated brake applications. Each brake application "uses" vacuum, so if the vacuum doesn't recover between brake applications you get reducing brake assistance.
Throughput is mainly controlled by the vacuum pump, but can also be effected by leaks AND / OR restrictions in the pipework (Kinked pipe ?) or by a faulty Vacuum Check Valve (Non Return Valve)
Item 1 is easy to measure with a vacuum gauge directly (as close to the brake booster as possible).
Item 2 is harder to measure, but is possible to get a good indication by emptying the brake booster (engine off, make repeated brake applications (more than 5) & then measuring the time until the vacuum stops increasing.
Hope this helps you re-check your system.
In an earlier post someone said the vacuum should be between 15~20 in Hg.
Actually, for a diesel engine or any engine with a separate vacuum pump, the value should be quite a lot higher - typically 25~30 in Hg.
You made a comment in a previous comment that the brake pedal would sink faster after the engine started with the original alternator.
I think this suggests your original vacuum pump was much better for vacuum & probably throughput.
There are 2 important performance features of the pump :
1 - Maximum vacuum level - eg 30in Hg
2 - Throughput - ie how fast it can generate maximum vacuum level from a lower level.
"Throughput" is very important because it effects how good the brakes are if you have to make repeated brake applications. Each brake application "uses" vacuum, so if the vacuum doesn't recover between brake applications you get reducing brake assistance.
Throughput is mainly controlled by the vacuum pump, but can also be effected by leaks AND / OR restrictions in the pipework (Kinked pipe ?) or by a faulty Vacuum Check Valve (Non Return Valve)
Item 1 is easy to measure with a vacuum gauge directly (as close to the brake booster as possible).
Item 2 is harder to measure, but is possible to get a good indication by emptying the brake booster (engine off, make repeated brake applications (more than 5) & then measuring the time until the vacuum stops increasing.
Hope this helps you re-check your system.
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