Technical Strange Brake Problem

[Bravo Brough]

Hi, I have a 1.9 MJet 120 (78000 miles). The EGR valve was clogged and causing problems. So yesterday I took it off and soaked it in oven cleaner overnight. However, I had to use the car this morning for a 30mile round trip.
It went ok (albeit a bit blowy), but then the brakes stiffened up (as though the servo had stopped working), with a solid pedal.
I re-fitted the EGR valve this evening, hoping that the brake fault might be something to do with a lack of vacuum, but it is still the same.
Any ideas folks ??

 

[portland_bill]

A diesel engine does not create a vacuum in the inlet manifold, so it has a vacuum pump, probably driven from the camshaft. Have you disconnected a hose? Or connected one incorrectly?

 

[Bravo Brough]

No,
Everything went back as it came off. Are there any fuses/relays that could have popped? I am guessing that the brake fault is related to the EGR removal and re-fitting, but I'm not sure.

 

[aurick86]

I think the vacuum pump is mechanical, when the engine rotates it also rotates..so no fuses or relays.
Find the vacuum pump pull off the hose/pipe going to the brake servo.. and check it actually makes vacuum.
If it is working, you would need a hand vacuum pump with a gauge, use it to pull a vacuum on the brake servo.. if it doesn't hold the vacuum then replace the servo.

 

[Bravo Brough]

Thanks Aurick.

That'll be a job for tonight then

 

[Bravo Brough]

Had another look just now. I'm guessing that the vacuum pump is on the righr hand end of the camshaft (looking from the front). It has a rubber hose to the brake servo.
Took the hose off whilst the engine was running, but felt no vacuum.

If I'm in the wrong area folks please let me know.

 

[aurick86]

This is the vacuum pump fitment/removal procedure:


that's what you should be searching for.

Get the code off the pump to see if it's the same one that the Stilos used. You can find Stilos easier in breakers yards, for a nice cheap fix.
A new pump seems to be around 150 euros.

 

[Bravo Brough]

Yes,
That's what I was looking at

I'll get the code and start searching...................thanks again.

 

[Bravo Brough]

Just looked on Euro Car parts. A Pierburg Vacuum pump (model number 131580030) is £99.00.

 

[aurick86]

Seems about right.
Just keep us posted.

 

[Bravo Brough]

Sorted


After carrying a full fault finding task, the problem was found to be a split in the vacuum hose T piece (plastic). Replaced via a local motor factors at a cost of £3.20..............................Yea!


Many thanks to those that gave advice, it aimed me in the right direction.