Monday, 28 October 2013

Vacuum assist here we come.

Ok so I promised myself that now the kids birthday parties are out of the way and I have been driving the car with decidedly dodgy brakes for 2 weeks it was time to fix the vacuum brake assist.

I had already had an explanation of what was require by Steve as he also needed a vacuum assist on his MX5 conversion.

I had also passed this on to my mechanic who had fitted the vacuum sensor and pump, however he had fitted the sensor in line with the pump and vacuum chamber and try how I did to get the vacuum to work it would either not seem to switch on an off correctly, it either ran constantly (blowing 1 £40 sensor due to my idiocy of not fitting an extra relay to separate the motors high current from the sensors relay contact, Dummy!) or not to run enough ie. No vacuum!

After a little thought (it helps) It became obvious that because the sensor is in between the pump and the chamber it would switch off before the chamber had reached its fully evacuated state.

The solution to this was to move the sensor from the T in the pipe to the chamber itself, in fact the best spot turned out to be obviously the furthest point from the motor and there was a convenient flat point on the chamber on the opposite side to the motor tube outlet.

Of course this meant breaking down the entire hydraulic master brake cylinder, disconnecting the brake pedal from the master  cylinder and removing the whole vacuum chamber, separating the master cylinder from the chamber and drilling and tapping a hole for the sensor to screw into, luckily I had a tap and die set that had just one imperial sized tap and die, 1/8 of an inch exactly what I needed.

So after breaking it all down and drilling and tapping on Saturday afternoon/evening I cleaned up the surface corrosion around where the master cylinder joined the vacuum chamber and rust treated it with some Jenolite I had kicking around  primed it with the part 2 Jenolite treatment and once this was dry around 10:30 Saturday evening, I finished it off by slapping some black enamel on it ready for Sunday’s reassembly.

Spent Sunday morning reassembling the whole shebang and testing it, worked a treat and now I have fully functioning vacuum brake assist, however this merely pointed out that the beat has s#!t brakes! :-(

So I guess I am now in the market for some new brake pads until I can get some 15” deep dish wheels (as recommended by Brad a work colleague who knows and likes his cars) according to Brad I have 14” x 5” wide wheels/tire’s on the rear and 13” x 4.5” wide wheels/tires on the front, he has recommended I get at least 8” & 9” wide wheels for the extra grip that I am now decidedly lacking.

Update on what is left to do

1) Get the Tax disc Done
2) Repair and get my 12Kw EMW charger working.
3) Fix speedo issue
4) Test brakes properly and fix if necessary Vacuum Assist Done, better brake pads needed!
5) Fit last battery box and test PSU/DC-DC converter. Done
6) Full test of all systems, lights, indicators, brakes, windows, anything that draws current from the 12V batt whilst the car is driving around the garden. Done, PSU works treat (Thanks Steve)
7) Assuming charger is working now, fit into Ali box and test again
8) Fit charger into car and wire J1772 (there are issues here that Valery and others are trying to resolve)
9) Wire J1772 plug through an adapter to my supply at home and test all systems work as expected.

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