Brake or Vacuum issues

[wewantutopia]

So I just finished installing a new remanufactured IP and timing belt. That all works great but I drove it today and I need to apply massive pressure to the breaks to stop; like there is no power breaks.

Thinking it may be a vacuum issue, I tried adjusting the heater controls and there is no change when switching from defrost, to feet, to dash etc.

Is the vacuum pump related to the IP somehow? Is there something I could have done to the vacuum pump when R&Ring the IP?

I suppose before I start jumping to conclusions, is there a good/cheap way to test the vacuum pump?

It looks like I have the vane style pump not the diaphragm pump.

Also, I own the Bentley... I can't find the vacuum pump in the index. I read when searching the forum that the manual talks about the pump. Where is it in the book!??

Thanks!

[82vdub]

You probably knocked a line off somewhere, or the small line that goes into the cab pulled loose and it's not able to build vacuum. Isolate the vacuum lines. Pull all of them off the vacuum pump, plus the holes and see if the pump itself builds vacuum. If it does, it's a line or fitting somewhere, if not, it's a pump (which I highly doubt). It's probably so obvious (when you find it) that's it's so hard to see.

[Quantum-man]

Just get Yourself a vaccuum gauge.
Like the one used for balancing carbs, and testing fuel pumps combined.

This also makes a good boost gauge/airfilter clogging gauge. They are often "10psi-zero-30" WG"

Attach to vane pump, and should reach 25WG rapidly , and with idleing engine, only diminished with rapid applications of foot.
Should hold vac until tommorow minimum

[82vdub]

I have a good vacuum gauge, but for a quick reading, I will grab by Mity Vac brake bleeding tool that has the gauge on it. It's accurate enough to be able to tell you if your pump is building vacuum or not, and it's cheap and works as two tools in one

[wewantutopia]

thanks for the replies, I'll check tonight.

Where in the Bentley does it talk about the vacuum pump?

[TylerDurden]

The MK2 Bentley doesn't say much of anything about the vacuum pump itself. It gets mentioned in the brake section.

[wewantutopia]

The MK2 Bentley doesn't say much of anything about the vacuum pump itself. It gets mentioned in the brake section.

ok I thought I was going crazy.

how is it installed? just bolted on? is there a gasket?

[Dakotakid]

O-ring located at base.

[82vdub]

The vacuum plays a vital role, not just to make vacuum. It's driven by the intermediate shaft, from the timing belt. The intermediate shaft interfaces with the vacuum pump, and the bottom of the vacuum pump shaft integrates with the oil pump. So, you've got to mesh the vacuum pump with the oil pump properly. If the pump doesn't seat properly on the block, you can rotate the oil pump shaft a bit and try to get the two to mesh together properly.

[TylerDurden]

Seals:

The small shaft seal (from dealer): 068 145 117 B

The block/flange o-ring: 068 145 119. (A spare water flange o-ring works too. 037 121 687 )

The lid o-ring is reportedly the same as the IM shaft carrier o-ring.

[wewantutopia]

Ok, I FINALLY got around to checking this...

I unhooked all the hoses from the pump and hooked up my break bleeding vacuum pump (great idea by the way) and was getting between 25 and 28 instantly and sustained.

I rehooked-up the vacuum lines and attached the bleeder pump to the barb for the heater control line. It wouldn't get over 5. hmm.

As I was fiddling with the little barb, it broke... damn.

I spun the fitting that comes off the pump for the lines to attach to so I could look at the damage done and low and behold it looks like there is an even hole above the one I broke (I assume it used to be a barb that also broke).

I temporarily covered both the holes with generous amounts of electric/hvac duct seal putty and the breaks work great!

So... what usually attaches to the vacuum pump? Obviously the break vacuum assist and the heater controls, is there a third thing? What could the other little hole be for?

Also, does anyone know the part number for the fitting that attaches to the vacuum pump that all the lines attach to (sorry I don't know what to call it)?

Thanks!!

[TylerDurden]

Those damned barbs suck, lol. They break if ya just look at em.

IIRC, the delicate fitting is a joke by VW to sell you an entire pipe - there's a check-valve at the top. I'd ghetto-fab in a bigger barb with epoxy and use a reducing nipple/fitting (Dorman, etc.) to supply vac to the heater controls.

Another device using vacuum will be cruise-control.

[Quantum-man]

An 'upshift' LED may also be the missing link [er barb]

[wewantutopia]

Thanks for the replies!

I'm pretty sure I had an up-shift indicator that I immediately disconnected when I got the car. Didn't realize it required vacuum too. So, that can go.

Is the check valve required? Can I just use a vinyl "Y" barb?

[TylerDurden]

My upshift indicator is integrated in the transmission multi-pin electrical connector - no vacuum used AFAICT (maybe on gassers).

The check-valve is a safety component to keep the brake servo energized regardless of engine speed. (Of course, if the engine stops, the vacuum in the servo will deplete with use of the brakes.)