bill'sMB

Like many others, I have been chasing air leaks in my trunk lock air controller. I found a closely related air leak in the coupling where the yellow tube airline attaches to the PSE pump at the HECK location. I thought I had the problem solved when I purchased the coupling from the dealer but soon realized that I did know the technique to attach the tube airline to the very small 2.5mm diameter airline on the coupling. The tube airline has to be heated so that it can be pushed onto the coupling. I have searched for and found only one reference for a technique to do this. I hope there is someone out there that can give me specific instructions on what heat range to use on the heat gun, how long to heat the tube airline prior to attempting to push on the connector etc. I read that the tube airline and connector should be cooled with a damp cloth after the coupling is pushed onto the heated tube airline. The heat to be added to the tube airline will depend on the material of the tube which I don't know at the moment.

Any help in doing this critical step will be much appreciated.

Lotus GT

How about buying some used parts from the guy parting out his car to use as practice first? You could test at different temperatures to get the best fit.

DavidCA

Bill,

Why don't you just change the "O" ring, the yellow ring easily pops out?

elMacko

That is an old trick to soften any plastic hoses when pushed into a barb fitting. You just have to heat it till get soft. If you want to be conservative, get a jug with boiling water and submerge the end of the tube for a minute, then rapidly push the end into the barbed connection! Done deal...!

bill'sMB

I took the advice given to me today by elMacko and with 30 minutes of heat gun training successfully reattached my yellow airline to the new coupling. That is the good news. Unfortunately, I'm still blowing air from where the new coupling attaches to the PSE pump when the trunk soft close is working. I pressure tested the new O ring at 50 psi - seems fine to me. Either the PSE pump is not shutting off as it is supposed to do or the connection to the PSE pump is not correct. I can move the coupling back and forth and hear the air noise change.

bill'sMB

I did reattach the yellow hose and am still blowing air by the new seal that is in the new coupling that is installed and connected to the HECK PSE outlet. I set the pump for 3.5 bar. I'm inclined to just live with the situation for the time being unless you think I'm missing something obvious. I suppose the outlet on the PSE pump itself could be bad or worn out. Either that or something inside the box itself that is not shutting off the pump. The fact that the remainder of the PSE functions work tell me to just live with it the way it is for now.

bill'sMB

A few details on what was used to attach the yellow air hose to the coupling ( part # 202 800 05 53) that connects the hose to the PSE pump.
Parts used: Heat gun (SEEKONE), digital meat thermometer. The air gun is very inexpensive but it did the job.
Set the temperature of the air gun discharge to 350 degrees F.
Aim the end of the hose to be attached to the coupling directly into the air stream for 10 seconds about 3 cm from the gun air outlet after you have reached 35.0 degrees. Make sure the temperature has stopped increasing when you are ready to attach the hose.
Quickly push the end of the hose onto the coupling.
Wrap the hose and coupling in a damp cloth to cool.
Shut off the heat gun.