I previously wrote about this matter as I’d purchased a Gunson self bleed kit that needed adaption in order to work. Wiser members than myself advised me not to bother and they were right in that having bought and adapted a second hand master cylinder cap I found that the Gunson bottle itself leaked air and so ended my experiment of renewing the fluid by blowing it out of the system.
One reply to my previous post advised using a self bleed kit that works on a one way valve principle and these I have ready to use if all else fails. The only problem I have read about these is that doing the job one handed you cannot hold the pedal depressed while you close up the bleed nipple and as a result air can get in via the threads of the bleed screw. I have read that this can be stopped by using grease around the threads of the bleed screw, but as yet I am not certain how effective this will prove. So at the moment pumping the fluid out of the system is on hold.
The last option is to suck the fluid out of the system via the bleed screw and to this end I have been lucky that the Sealey Oil Extractor I bought that works very well extracting oil from my engine also has a pipe included especially made for attaching to bleed nipples. It comes with no instructions of course but the theory seems quite simple that you pump the machine after attaching the pipe to the nipple and the carefully undo the screw and monitor the fluid coming out and shut off the screw every so often in order to top up the master cylinder. In theory this method should avoid the problem of letting air in to the system due to the direction of flow of air and fluid. The only issue that concerns me, and which I would be grateful for members views, is that I have read that the suction can reverse the rubber seals in wheel valves.
I know people are going to suggest that I should just get the assistance of my wife, neighbour or friend to simplify this job, but as others have mentioned when doing this job their are as many pros and cons to doing this, as to doing the job single handed.
I’ve bleed brakes in the past and they’ve been one job that for one reason or another has always had problems. So before doing it this time I want to try and use a method that’s the most simple and effective, which yours might be. In truth I almost tried it yesterday only to discover that I didn’t possess the right spanner for the brake screws.
Dead easy solution to bleeding your brakes yourself is to buy and fit Automatic Bleed Valves. I fitted these about 10 years ago due to all of the problems associated with this job. You start by opening the valve furthest away from the Brake fluid tank, by about one quarter turn and pump the brake pedal a couple of times. All you have to do is to make sure the brake fluid tank stays topped up between each bleed, don’t let it get emptied.
A number of posters on this forum have advised that the speed bleeders corrode and the spring loaded ball in the units rusts up and stops working. Meaning a new speed bleed nipple is required.
I put something like those ages ago on my bitsa and bought a bag of assorted spare boots (from Midnight Motorist in Greenford) to cover the grease and brake nips, as they always seemed to split when removing them.
Those lasted eight years of commuting until I scrapped the car.
I found these nips boots on ebay, but don’t know if they are any good…
Just a follow up to my last message. I did the brake and clutch fluid renewal today using your suggested one way tube, but as I said previously doing this job has never been straight forward. So having now bought an 8mm spanner I took off the rear offside wheel only to find that it was too big, fortunately guessing something like this would happen on my trip to Halfords I’d also bought a 7mm and 6mm and the 7mm fitted. The other three brake bleed screws were the normal 8mm. Go figure.
Agreed with Robbie it suggest a replacement caliper if the nipple hex size is different from the three others. I have had to fit replacement calipers around 30k miles to our Jeep and 40k miles on my Mk3. also 40K miles on our Scooby and that did most of it’s miles in town.