Tricky Aircon Pipe

[davidr]

I took a look at the heat sleeve over the vacuum pipe that goes between the throttle body and the brake booster and it wasn't good. Thankfully there is a quick connector where the pipe transits through to the booster so it's easy to pop that off, slide off the old sleeve and slide on a new one.

Old and new sleeve on the bench. The old one is starting to break down. There are a lot of hot things in that corner of the car so I don't want the vacuum line to melt so I lose brake assistance. That may not be funny in a car capable if 155mph!

New sleeve fitted

[davidr]

The upper part of the 2 part hose is not available new. I thought I was onto one from SNGB but it turned out that their supplier couldn't supply. I turned to eBay and ordered a used one from Germany that arrived surprisingly quickly.

I treated the used pipe to some new O rings

Then it was just a case of threading the pipe through under the throttle body and connecting it at both ends

[davidr]

My thoughts then turned to the heat shielding. My reckoning was that there were 2 issues here. Firstly the heat shield over the catalytic converter was missing - probably had been removed and not refitted when a previous owner had a lambda sensor changed, and secondly the heat shield over the exhaust pipe to the EGR valve had a hole in it which I think is how the flexible aircon hose was exposed to heat and breached.

Hole in heat shield

Heat has melted the flexible section of the aircon hose and caused a leak

The exhaust pipe for the EGR valve (centre) runs very close to the aircon return pipe (at the bottom) and the vacuum pipe to the brake booster (at the top). I have made sure that both are now protected with heat-resistant sleeving.

The heat shield that should be above the catalytic converter is missing

[davidr]

Despite contacting both Eurojag and Autoreserve who haven't given me the courtesy of a reply I haven't been able to source replacement heat shields so I thought at least I could try repairing the one I had.

I used JB Weld to pull the composite back together

And then covered the shield in aluminium/fibreglass tape. I'll be the first to admit that the job is more functional than aesthetic!

Once installed I'm hoping it will do the job.

Here is the heat shield installed and hopefully the additional protection will prevent a recurrence but I'd still be happier if I could find a replacement heat shield for the cat.
So now here comes the proof of the job. I took the car down to Will at Hollygrove in Ringwood (01425 477000) and we gave the system a thorough vacuum and leak check that I'm pleased to say it passed and so we gassed it up with 675 grams of R134 and fired it up. Success! The system is blowing lovely cold air!

[J44EAG]

Nice one, David.

Worth noting that Viper Performance offer a full range of modification goodies for race and rally cars. Its worth perusing their online catalogue when it comes to finding materials and equipment to build one off parts. ie heat shields and the like.

Mike K

[davidr]

Hmmmm. It would appear that my moment of triumph was premature. When I used the car today the aircon wasn't working. I checked the pressure in the system and it was low. So it appears that I have a leak somewhere.
We put dye in the system so I went round all the pipe work with a UV torch but couldn't see any sign of a leak - certainly not on the newly installed pipework.
Prime suspect would have to be the condenser I guess.

[mike020150]

How frustrating! I have a car with a similar issue. I sympathise. Back to the drawing board. Mike.