Series 3 Diesel vacuum pump question

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Jules59

Member
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45
Location
Warwickshire
I have a question about the vacuum pump on my diesel S3 project re-build. The pump has two inlet ports (I think they both suck). One goes to the brake servo (pipe attached). What is the other port for ? Should it be capped off or left open ?

S3 (49) (Large).jpg
 
I have not ever seen one of these in the flesh, most series that had a servo had a flap device in the inlet manifold to provide the vacuum [ pretty rubbish ]. For yours to work both inlet and outlet need to be open.
To test pump remove pipe and with engine running [ careful as rotating parts near ] and put a finger over each pipe in turn. One should suck and one should blow. Pipe needs to be on the one sucking the other should be left open.
 
Where does it exhaust? If there is no exhaust then that could be it.. If it is the exhaust put a bit of pipe on it and route it somewhere where dirt and water wont block it.
 
One sucks for the servo and the other is the exhaust
That same vacuum pump used to be fitted to fords with the old Peugeot engine
 
the standard set up uses the inlet manifold for vacuum as tottot says this then Tees off and one goes to servo and th either to a vacuum reservoir storage tank , to make it work well the butterfly valve needs to be adjusted properly using the adjustable levers
 
I have not seen a vacuum pump like that before. My series three ha the butterfly arrangement on the inlet manifold, as stated before a bit of a rubbish set up.
Add on to the poor set up of butterfly arrangement 30+ years of wear and you will never get it working well.
My solution was to bin the butterfly and blank off then fit an electric vacuum pump triggered from the brake light switch. Two hours work and sub £100 all in.
 
the standard set up uses the inlet manifold for vacuum as tottot says this then Tees off and one goes to servo and th either to a vacuum reservoir storage tank , to make it work well the butterfly valve needs to be adjusted properly using the adjustable levers
Certainly no butterfly valve on this diesel's inlet manifold that I can see.
 
Could you take some pictures to show how the pump in the first post is mounted? I'm trying to add one to my 2.25d and would be interested in the mounting arrangement.

Many Thanks,

PM
 
I have not seen a vacuum pump like that before. My series three ha the butterfly arrangement on the inlet manifold, as stated before a bit of a rubbish set up.
Add on to the poor set up of butterfly arrangement 30+ years of wear and you will never get it working well.
My solution was to bin the butterfly and blank off then fit an electric vacuum pump triggered from the brake light switch. Two hours work and sub £100 all in.

Interesting. Which Vac pump did you use pls ? I'm toying with an electric conversion on our 300Tdi's ;)
 
Disco 1 BFG, From memory I used a Hella U28 or maybe a U30 ? I sold the series three a while ago so can't check.
I bought the vacuum pump from a Dutch supplier new for around £70 (badged as a Volvo part). Very simple to fit triggered via a relay from the brake light switch. It transformed the hit and miss servo flap arrangement into a reliable works every time set up. The only downside was that I could hear the pump working when sitting with my foot on the brake peddle. Chris.
 
Many Thanks - very helpful.

My pump has arrived and is of the same type. I now need to source the double pulley and the mounting bracket. I've never seen the part # for the latter or seen it advertised.
 
Optional parts catalogue shows a double water pump pulley for double belt fan set up.
 

Attachments

  • Double water pump pulley.JPG
    Double water pump pulley.JPG
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Thanks!

That's one part of the problem identified! Now just the pump mounting bracket. Forgot about the optional parts book. Must look for that on the early 110's, which had this fitted.
 
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