The spec will be the same as was except for the slightly bigger bore. Maybe that'll change in the future but for now I want to get it running. I still need to get it registered in Texas and I think I'm being fined every month that it's not registered after importing it. I can't register it without an inspection and insurance so I need to get it driveable first.
I'll try and update the spec on my web site over the weekend, there are a couple of items that are out of date.
Re: Fiat Coupe 20VT in USA - Discussion
[Re: Begbie]
#1671769 02/05/202415:0902/05/202415:09
Your tenacity in looking for the elusive/extinct brake master cylinder is much appreciated John, it would be amazing if you found something. I know experts here have torn their hair out in their quests....
BumbleBee carer
Re: Fiat Coupe 20VT in USA
[Re: Begbie]
#1672754 03/07/202415:3703/07/202415:37
The cylinder has two holes in the top into which the brake fluid enters. These have rubber plugs in them with a hole in the middle. On the FIAT (LHD or RHD) a 90 degree plastic pipe is inserted into the rubber plug. The other end of this pipe is connected to the rubber hose that goes to the remote brake fluid reservoir.
The problem is that with either the LHD FIAT cylinder or the VW cylinder the hole in the rubber grommet is larger and the plastic pipe won't stay put. For the LHD FIAT this is due to using a different sized plastic pipe. For the VW this is caused by the reservoir tank plugging directly into the cylinder. The LHD FIAT plastic pipes are no longer available. If I'm to use either of these cylinders I have to find another source for these larger diameter pipes.
I had a look on ebay and there is only one used LHD FIAT cylinder available. It is in very poor condition but I'd only want it for the plastic pipes. They should work but shipping to USA is about $70 and I'm looking for a easier to source solution that would also work for other owners who may end up in the same situation:
I've checked and the pipes used by older FIAT puntos and Bravos that use a remote reservoir are still available. Most modern implementations are plugging the reservoir directly into the cylinder. This makes sense in that there are less connections and parts. I'm going to order a pair of each on the chance that they are larger diameter.
Last edited by CanadianCoupe; 03/07/202418:40.
Re: Fiat Coupe 20VT in USA
[Re: Begbie]
#1672762 03/07/202419:2403/07/202419:24
These pictures might help explain the problem better, They show the rusty RHD FIAT cylinder and the new shiny LHD FIAT cylinder with yellow plugs.
The plastic pipe has a OD of about 8mm but the hole in the middle of the grommet for the LHD FIAT or VW is more like 12mm.
Yes the bores are smooth so an alternative might be to find a rubber grommet that fits into the hole in the LHD FIAT or VW cylinder but with an 8mm hole in the middle to fit the plastic pipe from the RHD FIAT.
Yes the bores are smooth so an alternative might be to find a rubber grommet that fits into the hole in the LHD FIAT or VW cylinder but with an 8mm hole in the middle to fit the plastic pipe from the RHD FIAT.
Putting aside the issue of swarf, for me the ideal solution would be to plug tap those holes and fit threaded barb fittings with thread seal and then plumb to a suitable new reservoir, difficult perhaps but I don't think impossible. Alternatively a rubber grommet or O ring could also work providing it is held firmly in place by the suitably rigid pipe insert.
What is the part number of the VW cylinder?
E85
Re: Fiat Coupe 20VT in USA
[Re: clanger]
#1672765 03/07/202421:0803/07/202421:08
Before plastic became the preferred material those little parts would of been made out of brass. In a similar vein to where the oil cooler pipes enter the sandwich plate and are sealed with an O ring, a shouldered brass insert with with O ring and either a barb or threaded stub as a take off could easily be produced by someone with a small lathe. The ideal person would be someone who makes model steam engines as it is similar in scale and they produce such parts as a matter of course.
I think you are already more than half way there in finding a replacement cylinder that physically fits.
E85
Re: Fiat Coupe 20VT in USA
[Re: Begbie]
#1672769 04/07/202410:3604/07/202410:36
Something similar to that brass item in the link would work except that on the FIAT the outlet needs to be at 90 degrees because the remote reservoir brake lines come in from the side not the top. I'm looking at alternative plastic fittings to make it as easy as possible to convert.
I think the LHD FIAT cylinder is longer only due to the design. As long as the internal cylinder is the same diameter (7/8") then the amount of fluid pushed down the brake lines should be the same for the same pedal movement. 7/8" = 0.875" = 22.2mm