# Vacuum pump reservoir - math



## O'Zeeke (Mar 9, 2008)

jlsawell said:


> Can someone please check my maths?
> 
> I'm putting together the PVC reservoir for my Thompson Vacuum pump to power the brakes.
> 
> ...


Hi jlsawell, i had no idea cheese was metric. Anyway i think your math is right except where are you going to stick 2 tubes 1.273 meters long? I dont think it matters if you have 1 tube 2.5 M long or 10 tubes .25 M long connected together except for the greater amount of joints to leak. Check out http://www.driveev.com/jeepev/convpgs/pbrakes.php Can you get 4" (9.8cm)pvc? I think the length could be decreased by a factor of 4 making it easier to fit it in. Hope this help a little, if not i have a friend Dave who has a Ph.D in math who might to be able to figure it out.


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## jlsawell (Apr 4, 2008)

O'Zeeke said:


> Check out http://www.driveev.com/jeepev/convpgs/pbrakes.php Can you get 4" (9.8cm)pvc?


Thanks O"Zeeke, that Jeep link is exactly what I'm looking for.

The 2.5m tube won't fit anywhere but I was thinking I might fit 2 x 1.2m tubes across where the radiator used to be. I'll have to do some measuring of the car but so long as the math is right I'll be able to fit something together with a visit to my local plumbing supplies warehouse.

Much obliged for that url!


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## jlsawell (Apr 4, 2008)

OK, for about $20 at my local Bunnings Hardware I got 1m of 50mm PVC tube, two end caps, 4 washers, 2 brass hose nipples and 2 brass locks for the inside. 3m of vacuum hose cost me $12 at the local auto parts store. I cut the tube down to 80cm, as this will give me about 5 litres of vacuum.

(2.5cm x 3.142)^2 x 80cm = 4.9 Litres

Then when I got home I learned that the thread on the brass nipples is about 1/2 inch - a lot larger than the largest drill bit in my kit. Back to bunnings for a drill bit and I also picked up some silicone sealant and a gun. I drilled a hole in the end caps, fitted the washers and nipples to the locks and sealed all around them. Pushing the vacuum hose onto the nipple was a bit of work, but then tightening up the hose clamps was the easiest part of the job.

So: here's my finished setup. I've checked that it will fit in the car in front of the radiator, using cable ties to secure it to the body.

Now all I've gotta do is afford the vacuum pump from ZEVA.

And do I need to keep the radiator? My gut feel is to chuck it, so long as the transmission doesn't use it for cooling, right?


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## e_canuck (May 8, 2008)

Hello jlsawell.

Nice. Glad you are making headway.

I did'nt follow all your steps. But the radiator is for dissipating the heat from the ICE. I see very little use for it. On my donnor the rad also old the AC's own rad and one inertia switch for the airbag.

If you have stuff hanging from it, you might have to reposition them or manufacture some brackets.

Your reservoir is very long, therefore thin. Brian's first build colapsed.
http://www.diyelectriccar.com/forum...on-build-thread-15586p16.html?highlight=brian

review thread #159.

You might have to do similarly.

I am also waiting for my pump. Expensive "sucker" is'nt it?

Take care,

DP


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## jlsawell (Apr 4, 2008)

e_canuck said:


> You might have to do similarly.
> 
> I am also waiting for my pump. Expensive "sucker" is'nt it?
> 
> ...


I will probably have to do similarly - have to see when the pump arrives. They are expensive suckers. I am sure Cuthbert Calculus could invent something cheaper...


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