So getting my AC recharged and the low side cap is missing. I know that only protects against small leaks in valve but more for keep debris out. So i spent 4 dollars on the kit from local auto store thinking all caps were the same size. Well I was wrong. The threads are to small in the caps I got. Not sure what size they are and curious if anyone does? I see and 8mm cap and 9mm thread size caps on ebay so hoping it might be one of them

 

There are 2 different sizes on R134A(CFC free) systems (which is what your Disco is) There is a large and small and they are standardized for all cars with that system. There is also a different size cap for the old R12 systems. I don't remember what sizes the low and high side are but measure the inside of the cap you still have and order the other size. In a pinch you can cut the finger off a rubber glove and rubber band it over the port. (Bubba fix)

 

OK good to know only two sizes. Thanks

 

When they went to R134A they use the different size ports to make sure the tech doesn't hook the hoses up backwards. (how did we ever manage on the old systems that only had 1 size of fitting). Oh, BTW, most auto parts stores sell the cap, just take the one you still have and tell them you want the other size.

 

OK I misunderstood you first comment now that i have re read it. I did buy a kit that had two caps in it. One for high side, one for low. You are correct in saying the ports are different sized to not accidentally hook up gauges incorrectly. But that is true only for the outside i am finding out. The threads are on the inside of the port can vary and while the low cap i have fits the outside ok it never bites the inside threads. After much searching there is a 8mm, 9mm, and 10mm low service port thread size.

The 8mm is the normal size or the size in the auto stores as it fit on my Ford Fusion perfectly and in fact the Fusions cap has the thread size printed on it. Think i will order a 9mm to start with just because the 8mm feels close and measuring it with measuring tape (which 1mm difference is hard to tell with measuring tape in the somewhat dark) it did look to be 8 to 9mm.

I will also add the high port cap isn't standard sized either. The cap in the kit and on Fusion are interchangeable but the one on the disco is to large


Update for future reference. The universal kit that autozone/advanced auto and other shops sell are the 8mm version of the cap. I ordered a 9mm from ebay and it is the proper size. Just search for FJC 2613 and that is the proper low side replacement cap size needed

 

hi.. I know that it is an old thread,,, but I need the hi side cap.. the big one...does any one knows the size of it??? I buy the same kit at autozone .... but doesn't fit...

thanks

 

Ha ha, I did the same thing and got a kit from Pep Boys and they didn't fit. Thanks for posting the part number for the correct size for the low port. Ordering one now.

 

hi.. just for info.... if some one else need it....

I bought an AC kit.. p/n MT2909 at eBay... it comes with 6 different caps an 4 valves... this one has the two caps for the Disco 2.. High and Low.. for about 10 dlls...
hope this works for any one..