Hi all, going to get a boost leak tester made up tomorrow, I've read of two methods of doing the test...

 

Can I just attach the airline end to where the MAF sensor is and pressurise? or do you need to remove the hoses from the throttle bodies and put blanking plugs in each one?

 

OR are both methods just as good as each other?

 

Thanks in advance!

 

Kane

I've always made something up that goes where the maf is, never had any problems thst way.

test it all in one go....

As above be carefull not to put more than say 5psi through it aswel. Some soapy water does wonders to find the niggly ones.

using Maf bung is the better way .. but don't go beyond your Max running boost as theirs no point doing it any higher

you may find u have little Leeks coming from the IN-Take side IE pipes from Maf to the front of the turbo

if u do fine u have a small one No panic as this is used for Sucking the air in .. Not under Vacuum or positive boost

I was always under the impression that you shouldn't pressure over 5psi mark as it can cause damage and that any leak even if its in the vacuum side is bad as a vac leak would allow in in metres air that could cause a lean mix

if your Max boost is say 15psi .. then regardless of what your doing with the compressor Long as u dont go mad with it u be fine ..

 

all your Brake/clutch servos are on a one way valve and don't allow Positive pressure to enter the servo ... Only Vacuum ( Suction )

the other items on the car are are solenoids yet again the Pressure will not do anything

Boost leak testers are available to buy but I don't know a UK stockist, only US. You can remove the MAF and make a blank with a suitably sized coffee jar lid or similar. Drill a hole through it and put a tyre valve through it, then seal the outside with plumbers tape (PTFE tape)

 

I would pressurise to running pressure as well, some leaks my not appear until a certain PSI reached but they are still there. Use soapy water in a spray bottle as suggested

if your Max boost is say 15psi .. then regardless of what your doing with the compressor Long as u dont go mad with it u be fine ..

 

all your Brake/clutch servos are on a one way valve and don't allow Positive pressure to enter the servo ... Only Vacuum ( Suction )

the other items on the car are are solenoids yet again the Pressure will not do anything

 

You will also be applying pressure to the cam covers via breather system and the I spose the entire oil filled engine in the process though mark, which could potentially not be very good for cam seals and all those little bits and bobs, hence why they say 5psi, this should be enough to spot the leaks esp with the soapy water trick on board :D

You will also be applying pressure to the cam covers via breather system and the I spose the entire oil filled engine in the process though mark, which could potentially not be very good for cam seals and all those little bits and bobs, hence why they say 5psi, this should be enough to spot the leaks esp with the soapy water trick on board :D

 

your PCV valves should stop that..thats what there for. And anyway you would be hard pressed to spot leaks at 5psi never mind keeping it at that low pressure.Working boost pressure is what it gets every time its run so all,s good.

Nope, because of where pushing from. The intake/ accordion pipes are directly linked to the cam cover with no such non return. 5psi is the recommended pressure as static pressure is different in any event to running conditions. Z1 pressure test at 10psi and blank that front breather to prevent the issue.

Wow cheers guys, seem to have started a pretty interesting debate here, had a blank made up today, so will have a go testing it in the coming week. The reason I'm after testing, is that under boost, you can really hear air somewhere, and I think it's louder than it should be? Anyways, a test will rule that out!

 

While you tech guys are around... Is it common of the front brakes to get really hot under normal operation? The pistons don't seem overly sticky, and can be move by pushing with your hands, yet the pads do seem to to run on the disk...

 

Cheers guys!

 

- - - Updated - - -

 

Wow cheers guys, seem to have started a pretty interesting debate here, had a blank made up today, so will have a go testing it in the coming week. The reason I'm after testing, is that under boost, you can really hear air somewhere, and I think it's louder than it should be? Anyways, a test will rule that out!

 

While you tech guys are around... Is it common of the front brakes to get really hot under normal operation? The pistons don't seem overly sticky, and can be move by pushing with your hands, yet the pads do seem to to run on the disk...

 

Cheers guys!

the brakes on the 300 do get hot fast and yes the pads will all ways sit against the disc ...

 

just to test go and drive your car but dont use the brakes hard or very little for a few miles ..

pull over and see if the wheels are hot as well if there cool you will be fine both should be the same temp

the brakes on the 300 do get hot fast and yes the pads will all ways sit against the disc ...

 

just to test go and drive your car but dont use the brakes hard or very little for a few miles ..

pull over and see if the wheels are hot as well if there cool you will be fine both should be the same temp

 

The pads shouldnt sit against the disc or friction would build up,run out in the disc pushes the pistons back.

but pads do sit against the disc ... Not pressing but there next to it with in a fraction of mm ... but should not be binding Hence why i said to check the temp to see

Cheers guys, I'mm have a drive over the weekend and attempt to not us the breaks and coast to a stop after a few mins. They seem to be getting really hot, even on a couple of mile run without any really heavy breaking. Will let you know the findings of the 'no-brake' drive. :)