300Tdi Electric Brake Vacuum Pump

[130camper]

When I took the brake vacuum pump off my 300Tdi, to once again fix the oil leak, it was obvious that it would need major work or replacement as some of the "hard facing" on the operating plunger was missing.
However the camshaft lobe was also showing very minor damage. To rectify that would, I guess, mean removing the camshaft, ....... a lot of work.

I did remove and clean out the sump .... found a few very small pieces of shiny metal.

So I decided I would fit an electric vacuum pump for the brake vacuum.
I know this can be done in many ways, from assembling the necessary parts from wrecking yards, to using various new pumps and parts, all at varying prices.

My choice was an expensive one, took only a modest amount of time to fit, it seems to works well, and only time will tell if I wasted my money.

The CVR brand pump has relay and vacuum switch all in the one unit, thus saving sorting around for bits. Switch cuts in at 15 inch Hg and off at 20 inch Hg. Just bolt it in place and connect the 3 wires, there's even a piece of hose supplied in the box as well.

I bolted the pump on a made up bracket, with the vacuum tank alongside, inside the drivers side wing, behind the headlight.
A Series low vacuum switch was screwed into a fitting placed in the tank, it actuates @ 6-10 inch Hg and lights up a very bright light red light on a bracket on the dash board in the event of low vacuum.

The Series switch appears to have some thread that didn't correspond to any fitting I had, so I carefully ran a 1/8 BSPF 28 TPI die down it.

Only done 3,000 km but seems okay. Low vacuum light has never come on while driving. After 4 days of none use, switched "ignition" on, and no red light, pump started immediately and ran for 8 seconds.

CVR VP655 Vane style pump
12 Volt Electric Vacuum Pump – Cast Aluminum | CVR High Performance Racing Products (https://www.cvrproducts.com/2014/product/12-volt-electric-vacuum-pump/)

CVR pump $527 EMAustralia
Aeroflow Brake Vacuum Tank AF77-1018Blk $131 EMAustralia
Series Vacuum Switch 58219 $41 Brit Off Road
Red light and bracket (on dash) to warn of low vacuum $20 Local Auto Electrician
Plus a few other items eg cable, brass fittings etc.
Approximately $750 all up.

Andrew

[shack]

Good for you,
I had a go, albeit with cheaper parts than you, but had nothing but trouble with the vacuum switch and relays, it cost more than a standard pump as well, so now I'm back stock.
Hope it stays reliable for you

Cheers James

[AK83]

Curious as to what you did with the old vac pump?
Did you remove it's guts and leave it in place, or use a blanking plate on the block ... or ?

I'm kind'a thinking of doing something similar to my D1.

Been looking into options for a while now and I've also found a Hella unit(HLA009286001) that also looks suitable. EMAust have them for $470. Looks to be a more compact pump.

Question on your install:
you say after 4 days non use low vac light didn't come on, but that pump ran for 8 sec on ignition on .. does that mean that vacuum level was low but not critical?
Do you have a gauge on the tank to check the amount of vacuum remaining after a short non use period?

Reason I ask, is(worst case scenario kind'a thing!) .. you may be out in the bush, been using accessories heavily on the aux battery and depleted that, and out of the blue the starter battery is starting to play up too now.
Vac pump comes on automatically, and that short burst is enough to drop it to a level now that won't allow the engine to crank .. or whatever other situation could cause a similar end result.

Basically, my thinking is, to somehow set up the electrical side of the pump to only run/pump when the engine is actually running, rather than with 'ignition on'.
That way, the above 'flat battery hypothetical' will never be a problem.

.. anyhow good to see you're setup is and has been working. [thumbsupbig]

[130camper]

I removed the pump and made a blanking plate for the hole.

The HELLA UP30 12V VACUUM PUMP HLA009286001 pump was considered but for ease and time I went for the CVR because it has the vacuum sensor and relay all in the one unit......just connect 3 wires and the hose. Only time will tell if I have made the right decision.

To any one considering the electric vacuum pump replacement not all Hella pumps are suitable, some are for operating under dash accessories only.

Yes vacuum was low, but not enough to trigger the switch/light that is supposed to activate between 6 -10 inch hg.

I have not fitted a gauge yet, it was on my list as it would give an indication of the real vacuum available. I ordered one but the supplier then decided he didn't have it in stock.

I guess we all hope the failed battery situation never happens, and having the aux and starter batteries separated is a must. If the starter battery doesn't feel like getting up one morning there could be a problem. The 300Tdi must need quite a reasonable charge in the battery to kick it over. So if its low, would the pump take the last bit of charge or would it not be able the kick the motor over any way even without the pump?

I considered this and not being an auto electrician did not know if there is a way of activating the pump after start up. Relay off the charging circuit ?
Any suggestion from someone out there?

Hope that is of some interest

[AK83]

...

I considered this and not being an auto electrician did not know if there is a way of activating the pump after start up. Relay off the charging circuit ?
Any suggestion from someone out there?

Hope that is of some interest

Same here(ie. not an auto elec) .. but I was thinking having a relay coming off the fuel cutoff solenoid wire could work.
That way not only would it come on only after motor running, but also shut down after engine stopped too.

[strangy]

Seems a convoluted set up.(not a criticism)
Friends car has electric vacuum pump and doesn't have a tank. Activated a relay from the brake light switch thats it.
Commonly found on VE commodore etc and not expensive.

[130camper]

Hello AK83
The wire to the solenoid is live when the switch is turned to "ign" so that the motor can start.

Hello Strangy
Yes obviously one side of the brake switch is "ign" activated.
The other side, that I guess you are suggesting I don't think I would want to trust to assist stopping a 3.5 ton Defender.
Maybe with a tank in the system it would be okay.

The pumps I looked at all advised that an "ign" live supply was required.

[strangy]

...,

Hello Strangy
Yes obviously one side of the brake switch is "ign" activated.
The other side, that I guess you are suggesting I don't think I would want to trust to assist stopping a 3.5 ton Defender.
Maybe with a tank in the system it would be okay.

The pumps I looked at all advised that an "ign" live supply was required.


The vac pump has little bearing on the weight of the vehicle.
Ie the booster does all of this work 3,5 tonne or otherwise.
If I recall correctly ADR require at least 3 full applications of the system without vacuum, so as long you have a functioning booster and system the rest is essentially personal choice to have more than this by adding a tank.
Overkill considering it didn’t have it from factory.

Again no criticism just comment. I’m a fan of keeping it effective and simple.

[130camper]

Hello Strangy
Thanks for the comments you might know a bit more than me on this.

Looks like I might have wasted money and time fitting the vacuum tank.

Needed the vehicle going so perhaps didn't do enough thinking/research. When looking at electric pumps and kits the use of a tank was quite prominent.
Maybe to make more item sales the companies?

So you reckon a good electric pump can take the place of the 300Tdi mechanical, and if activated via a relay off the brake circuit should supply the vacuum quickly enough to supply the booster?

If so this could help AK83 with his low battery scenario and me to get back to a simpler system.

[strangy]

Yes, no probs supplying enough vacuum whenever required.
The install on friends car is activated when foot on brake only, so no power useage unless ignition on and foot on brake.
That setup sorts AK83 scenario also.

Apart from the noise of the pump when brakes activated (this one mounted inside) there isn’t any difference in brake performance.

If you have the tank etc and are happy with the install, I wouldn’t go changing it.

[AK83]

Yes, no probs supplying enough vacuum whenever required.
The install on friends car is activated when foot on brake only, so no power useage unless ignition on and foot on brake.
That setup sorts AK83 scenario also.

....

Sounds like it makes perfectly good sense.
Something to think about.
Reason I'm thinking of it, is my vacuum pump is currently 'leaking' small spots of oil every now and then .. so have to look into fixing it soon.

Having heard that the 300 Tdi vac pump is a known weak point, plus the issue 130 camper raised in his opening post(re the wear on the camshaft) .. just trying to eliminate as many potential issues on mine too.

Just as another 'hypothetical' install method, is there a timer relay type device available that could delay the operation of the electric vacuum pump say by 8-10sec or so after ignition is turned on?
I remember reading that the glow plugs are on a timer which operate for 8sec after ignition on, and stay on for that 8sec even after engine has started.

My 300 tdi starts in less than 1 sec, and I can't ever recall ever doing a 'pre heat' before starting either.

So(my thinking is), does a relay exist that would keep the circuit to the electric vac pump open(ie. vac pump off) and then close the circuit, and supply the pump with power after that 8 sec period?
.. or something to that effect.