Boost leak pump

[A80Avant]

I am trying to get a heavy duty pump,but still portable one to be able to test for boost leaks on my car without having to drive to the gas station,tearing the whole car apart,testing,and then put it back together to drive home....only to realise that i might not have tested enough,so i would have to go back down there again... etc etc

There are a couple of Michelin heavy duty inflator pumps that say they can go up to 50psi(which is 3bar). Now usually when we test we go up to 1.5bar or something,right? So wouldnt that be enough?

has anyone tried this before?
i know those foot pumps or the small ones for the tyres are worthless,but maybe something in between?

[terrybullwon]

If the leak is large you will not fill the cm3 quick enough that the pump will get it in there. You need a air compressor not a £60 pump.

[GazzaG60]

if the system is sealed you may be ok.

let em explain.

when i made a manifold for the 16vt i used the flange from a valve with subaru runners, platye alloy and stacks internally. to pressure test it i bolted it to a sheet of ally blocked the holes withsomething whe injectors go so it was almosr air tight.

with seaping air around the flange due to no gasket i only jsutr managed to accumulate 2bar pressure with a 3 phase compressor . flow and pressure are not ther same in that respect.

not sure how you do this but 2 metal caps one at the throttle body end, 1 turbo exit. drill the turbo exit one and fit a vac connector with a hose attached or a tyre valve i presume?

you will have to seal the ends of the pipes properly.

[newsh]

The noise of the pump will mean that you cant hear the leak anyway and as soon as you switch it off the air will be gone. You need a compressor, a small one will do, with an air reservoir so you can charge it up, switch off, then blow the air in quick with the tyre inflator and listen for leaks. Its also much easier to do at home without the traffic noise at the garage!

[A80Avant]

i never pressure check with all the hoses attached to the engine and turbo,because both the turbo and engine leaks from valve stem seals and turbo seals respectivelly.
I always check for intercooler leaks and tube leaks separatelly.I have ebough bungs to do that,so i tap the hose after the turbo and the hose that exits the intercooler for example and put the air in.This is an airtight system and should be able to hold 2bar right? it is like inflating a closed box with small amounts of hoses.

Then i will to the same with the inlet tube.

Arent those enough to check for leaks? Then the only thing that remains is checking the vaccum hoses,which again are not easy to check when pressurising the whole engine as hissing sounds do come from there.

i also found an air compressor from black n decker that can pump up to 160psi.

[AndyP]

It's not the pressure thats important, you need something with a receiver ( air tank ) that can put out a large volume of air quickly, a pump alone will not be able to do this. I have one of these

http://www.machinemart.co.uk/shop/product/details/ranger-24/path/diy-semi-professional-air-compressors-2

that can easily do boost leak tests. If you search on Ebay you'll find them cheaper, just look for a minimum 25ltr tank.

[A80Avant]

that would be ideal! problem about that is that i dont have the space to put it in as well!

if the leak is huge,then yes,it wont be able to pressurise.But if there is no leak,then it would be able to sustain a preset pressure inside the system i will have closed up,wouldnt it?

[AndyP]

that would be ideal! problem about that is that i dont have the space to put it in as well!

if the leak is huge,then yes,it wont be able to pressurise.But if there is no leak,then it would be able to sustain a preset pressure inside the system i will have closed up,wouldnt it?

In theory, yes, but in practise the small 12v pump your talking about put out such a small volume of air that it will take forever to pressurise the pipes and you'd never know if you have a leak or if the pump is still trying to put air in. Also, like John said the noise would be a problem, you need to get a large volume of air in quick, then some silence so you can listern for leaks.

[terrybullwon]

In theory, yes, but in practise the small 12v pump your talking about put out such a small volume of air that it will take forever to pressurise the pipes and you'd never know if you have a leak or if the pump is still trying to put air in. Also, like John said the noise would be a problem, you need to get a large volume of air in quick, then some silence so you can listern for leaks.

Your only the third person to try and explain this

[GazzaG60]

heres an example.

i have a pump for inflatable camping beds thats high flow. it will pump the bed in 1 minute but only pressurise to around 0.3bar. high flow

if you blow a bed up with a car pump it takes about 30 minutes. you can if you want add air until it busts. low flow (takes ages) high pressure (itll bust like a balloon)

fuel pumps and turbos are the same. most achieve a certain pressure but run out of flow.

[newsh]

Your only the third person to try and explain this

You give good advice, based on experience, but some people just dont listen..

The whole point is you're trying to see if you have a leak, what if you do?

[terrybullwon]

You give good advice, based on experience, but some people just dont listen..

The whole point is you're trying to see if you have a leak, what if you do?

Maybe alittle blunt

Right another way like gaz put it,

You have a swimming pool with 100,000lt of water

You need to leak test it as you are loosing water.

So you have 100,000 lt of water in bottles you have to squeaze each one in by hand this takes you 4 days. By this time you have lost 75,000lt of water and cant see where from.

But if you filled the swimming pool with a 1000,000 lt tanker to fill it with in 20 seconds your have all the pressure and alot more time to find the leak as the pool is full

So in sort as John said you need a air tank to get the air in there fast as possible

[newsh]

Yup

Hmm, blunt is not my usual style oops

[Rusty]

I use a double-barrel tyre pump. If you go at it hammer & tongs for 10 seconds then you can get about 0.5 bar in there, shows up the bigger stuff but not great. Other thing is to use a garage tyre pump, most are free, just don't use the pre-set type without lowering the pressure

[A80Avant]

yup,blunt as usual but it doesnt matter,since it is not easy to understand basing things only to theory

By the way a couple of models i was looking at were not 12V portable,but rechargable ones.

Im going to look for a tank type compressor then.
Thanks