These brakes have been the bane of my existence, but finally, I may have them sorted.
So I left off last time with testing the replacement servo, and finding out for sure that my old one was as leaky as a leaky thing.
Obviously that was no good, so it was time to swap them over.
To remove the old servo and master, first you suck all the fluid out with your handy dandy vacuum pump. Of course being a spit res, half of it is still full of fluid with no way to drain. Its OK, you can tip this out later.
With the pipes removed from the master, it was only a matter of removing the two nuts that hold the master to the servo. Then with some percussive persuasion, off came the master, revealing how much it had been leaking and stripping the paint off the servo.
To remove the servo, first you must remove the four nuts that hold it to the firewall. These are accessed via the drivers footwell area, and access is a heck of a lot better if you remove the glovebox first, but it’s still a nasty task to do. You also need to remove the split pin, washer and pin holding the clevis to the pedal.
But that’s not the really nasty part of this job. That goes to removal and refitting of the actual servo. The only tip I can give, is to protect your paint on the guard, and use some brute force. Eventually it will come free. Thankfully no signs of rust on the firewall, but there was some missing paint and scuffs, so I gave it a quick shot of Zinc paint to protect it.
Since I had the Zinc paint out, I also touched up a couple other spots that have caused me some bother. The strut tower and inner guard near the battery were covered in these little rust spots under the paint. No idea whats happened there, maybe a battery exploded in the past? Anyway, it needed to be treated and tidied up. A wire brushed it all back, treated the rust spots and sprayed Zinc paint on it. It’s not an ideal match, and it’s not gloss, but it will protect it and make it look black again until I can one day paint the whole bay properly.
The next day, when the paint was dry, I transferred the firewall-servo gasket to the replacement servo, and refitted. This was a pig of a job, but once again, protect the paint on the guard, and persuade it into place.
Interestingly, there are two different caps. The original res had a cap with removable center with the fluid level sensor, and a little red cup that sat in the neck of the res to presumably, smooth out any fluctuations in fluid level.
Because I could easily clean out the original cap, I chose to run with that one instead of the replacement.
So with everything buttoned up and no obvious signs of leaks, I started the engine up to check the booster operation. Obvious without bleeding the system I didn’t have any pressure in the pedal, but I wanted to check for any hissing. After a couple of minutes running, no obvious issues, and no hissing.
I did notice one thing though…. Since our garage is under the house I decided to get a Carbon Monoxide monitor and alarm for the garage, to make sure we don’t end up with CO silently killing us (we also have a smoke alarm in the hallway above that monitors CO levels).
After running Tess for a couple of minutes with the door behind her half open, we went from 0ppm (parts per million in the air), to about 85ppm. This isn’t enough to trigger the alarm instantly, but will after an hour or so of that level. Higher levels have shorter trigger times, but the effects can be felt from about 50ppm, and 100ppm is enough to give you a decent headache. 200ppm is a loss of judgement, and 800ppm will kill you in 2 hours. Its serious stuff. I opened the doors fully and the levels started to drop
These alarms with the monitor on them are cheap insurance, just to make sure you aren’t working in a hazardous environment.
Moving along, since everything was together and not leaking, I needed to bleed the system. This is where my new toy, the QuickJack, came into it.
I got the car in the air, with the lovely wife in the drivers seat, and set about bleeding the brakes. I started at the rear, and got nothing. No fluid at all. I hadn’t drained the lines, so I knew there was fluid in there, but the master wasn’t pushing it through. We had an air lock.
I had read horror stories about people having to bench bleed master cylinders, so I was hoping to not have that issue. I cracked off both of the lines at the master cylinder, and had my helper slowly pump the pedal. Eventually out came some air, followed by fluid, but only from the smaller line. I bled this until fluid came out freely, and then tightened the smaller line up. This then allowed the bigger line to bleed, so out came air followed by fluid.
Thankfully this restored normal service, and fluid (albeit full of air) flowed from the bleed valves on the brakes. I started at the rear and worked my way forward, getting all the old fluid, and air out. I had to bleed the rear a few times to get all the air out, and get good pedal feel. The old fluid in the rear was also cloudy for some reason.
So how do the new, completely overhauled brakes work? Amazing. Better than they ever have since I got Tess. The pedal is firm, but progressive with good feel. The brakes bite hard when told to, and no sinking or softness in the pedal. The pedal feel is much more like Effie, who had a very nice pedal. Hopefully I finally have the brakes sorted.
I took Tess out for a nice hard run to meet up with some friends tonight, and Tess is running better than ever. Obviously the servo was leaking vacuum and causing a lack of response and smoothness. Sadly the fancy (but old) Optima Redtop battery chose to give up tonight though (before I went out), so I swapped that for a spare I had around, but will need to buy a new battery soon as I removed that spare from Effie as it wasn’t starting easily. In the mean time it’s finally time to get some road time with her.