I have managed to strip the thread of the pipe fitting into the body of the wheel cylinder. I have a spare for every wheel but the right rear. I know they are impossible to find so what are my options to repair the thread without damaging the flare seat? Or does anyone have a replacement cylinder body to sell?
Terry Crossley
MKV DHC
Hi Terry, may I help by starting with some questions? Is the stripped thread on the pipe fitting or the wheel cylinder or both? The “H3158” is useful in the Jaguar parts manual, it also would help to learn if that number is on the cylinder and any other numbers on the cylinder castings as provided by Girling (or whatever cylinder brand is there now). Also, can you confirm type of rear axle assembly used here? Have you inquired with Cordell Newby (Western Jaguar) and also Simon Whitworth (of Worcester Classic Spares)? Once I know these answers, I can dig into my cross reference notes and also check in my spares. I got further information as I worked through my own Mark V brake system last summer.
HI Roger
Thank you for your prompt response
The stripped thread is in the wheel cylinder casting
Girling H3158 is cast into the moulding of the cylinder body. Stamped into a boss on the top of the casting are the digits HB98
I have a Salisbury rear axle
I have not contacted the suppliers you name other than to check their websites. Cordell Newby does not want to deal with Australia. I will send Simon an note.
Thanks again
Terry
Fixed pivot or sliding pivot?
If sliding pivot, here is mine, restored with stainless steel pistons and hoods.
The threads are not the sealing surface. Protect the flare seat.
If all else fails, you could either retap it to the next larger size end fitting, or tap it out to fit a thread repair insert. As I recall it is a 3/8-24 UNF thread, readily available here.
HI Rob
The machine shops I have taken it to are reluctant to fit a thread repair insert ( what we call a Helicoil) because it has to drilled or milled and tapped and there is a fear of damaging the flare seat when trying to get the insert far enough in.
I have heard of thread repair inserts which have the flare seat integral with the insert so it does not matter if some of the original flare seat is machined out but I cannot track one down anywhere. This is about the only issue that cannot be reconditioned with these things, and yet it cannot be uncommon.
Mine is sliding pivot.
Thanks for your response
Regards
Terry
rom: Rob Reilly [mailto:noreply@jag-lovers.com]
Helicoil is one type. Keensert is another type, and Acme is a third.
http://www.acmeindustrial.com/insert_comparison.html
You would not have to get the insert all the way in, as long as it was secured well with JB Weld or some other epoxy. You could get a long end fitting.
https://www.autozone.com/brakes-and-traction-control/brake-line-fittings
Hi Terry, here is update on my supplies.
Jaguar part number H.3158 for the body (H.3153 for assembly) also lists as Girling 301440. I also have a Girling book missing the identifying front pages which shows Mark V as using 390173 for right rear (and also says this is 1.1/2", so this needs double checking or being careful about diameters and brake balance among the cylinders).
My driver Mark V has right rear cylinder on Salisbury axle is Girling 412860 (with a Girling 301430 on the left rear).
My loose spare Salisbury has had the right rear cylinder removed. My memory is Rob Reilly has it now (can you confirm Rob? I can’t find it loose yet in my box parts).
The right rear cylinder likely is on my parts car, which I visit every few months.
Once I hear Rob’s reply, you can let me know if trip to my parts car is desired.
I just called Cordell Newby. He is away from his parts but believes he has new right rear cylinders as you might need. Off the top of his head he thinks they are a bit under US$300 and he says he is happy to ship to Australia.
Hi Terry, I had the same issue with a rear cylinder (the same unit as shown in Rob Reilly’s photo), with the solution supplied from my local brake and clutch repair in Geelong Australia.
They were able to supply of the shelf and male to male adapter that only require me to clean out the original striped thread in the cylinder feed inlet with a drill then using a “spark plug” tap of 10mm re tap the hole. the replacement unit then screwed straight in with the original pipe fitting able to screw into the adapter. there was not an issue with amount of material available to re thread the cylinder casing, different matter on the bleed screw area. Very easy and very cost effective. Can post a photo if that will help.
cheers Jeffery Hill Mk v sedan
Hi Terry, checked paper work, unit is described as Adapter 10x1mm - 3/8"
cost of $9.00. Spark plug tap is M10, 1mm pitch and 9mm tapping drill.
If can help more call me on 0412688532. cheers Jeffery
I only have one right and it is broken away at the bleeder port, no good.
The Autozone link I posted has dozens of adapter fittings which may be the same or similar to what Jeffery is describing.
Thank you all for the efforts and suggestions. I have been in touch with Jeffrey and have sourced an adaptor which we believe will fix the problem. It requires drilling and tapping a 10x1.0 mm thread into the 3/8 UNF hole in the cylinder body. The adaptor then screws into this. There is a flare seat in the adaptor and the original 3/8x24 UNF pipe fitting screws into the adaptor. Jeffrey is sending me a spare one he has and I have seen a parts listing from my local brake specialist which shows this adaptor freely available here in Oz.
Rob, I also have a spare RH cylinder but which is also broken away around the bleeder casting, so it must be a common issue. These cylinders are obviously fairly fragile and the bleeder screw is difficult to get access to behind the back plate when trying to bleed. It seems easy to damage the casting if one is at all ham fisted when adjusting the main or bleeder fitting. I now know how impossible it is to replace a cylinder body so we have to look after the ones we have.
Thanks again to you all, without you I could not have found this solution.
Terry Crossley