My midget's brake lights have stopped working today and I have traced the fault to a faulty switch. To my irritation the switch of the hydraulic type rather than a mechanical one. Swopping it out is obviously a simple enough task but clearly there is a danger of air getting into the system, resulting in me having to bleed the brakes (tedious). Does anyone know if this is likely to be the case and if I can do anything to avoid it?
Try removing the mastercylinder cap and placing some plastic food wrap over the top. Then re-install the cap. This prevents the reservoir from venting and might maybe prevent fluid from coming out when you take out the switch.
Hi. The plastic wrap over the reservoir is a good idea, especially when replacing cylinders or lines and you don't want a huge mess.
In my experience, though, the fluid dribbling out seems to keep air from getting in, and the plastic wrap might keep fluid from coming down from the reservoir replacing what drips out, letting air in.
Best bet is to have the new switch ready and as soon as the old one comes out put the new one in. Just have a rag underneath to soak up the fluid.
If working underneath watch for fluid in your eyes, wear goggles or something. You might have an assistant push on the brake pedal before you have the new one fully tightened, then hold the brake pedal down until you have the switch fully home. Good luck, I've never had problems with replacing the switch on our Land Rover or Midget (both have same switch). Oh, be careful with the brass four way connector, it is supposedly expensive.
I picked up a bleeder kit at AutoZone a few months back when I replaced my master cylinder. I can now bleed the entire system in under a half an hour, and the kit only cost about $5.
If you replace any part of the system, I would suggest bleeding it, since no matter how careful you are, there is always the chance that you have gotten air in there.