Published on 11/27/2018

Entropy is a universal constant that will always catch up with you. It erodes, it rusts, it wears out, it becomes brittle. Oh wait, I’m confusing my physics lessons with my car again.

The good news is that it’s been a long and fun-filled time with the car, but since September it’s been in and out of the garage all the time. Old age, a poor choice of an aftermarket part and some well, bad luck, have reared its ugly head in the shape of seepage and leakage of oil and brake fluid, and messed up my steering.

So after my rally (or dirt oval) excursion everything was covered in dust. Even the underside of the hood. It’s always fun cleaning up after yourself! But, it also became very visibly obvious that I had a problem - the valve cover gasket was leaking.

Fine Malmesbury dust

This is a very simply rubber seal that fits all around the cover and along the middle around the spark plug holes. This cover has to come off when the timing belt needs to change and so on. And, for 8 years, every time I had to take it off I put it back with the same seal. Never had problems. Then last year during the annual service I saw that the no 4 plug was a bit oily. Heh, so probably time to replace that gasket then. So I did, along with the cam angle sensor seal. Except that I bought an aftermarket gasket. It fitted fine enough, but almost exactly a year later it started seeping oil along the entire length of the valve cover, on both sides. I guess that explains the (very big) difference in price from the OEM gasket. So of course I waited a few weeks for the Mazda one to arrive.

But to replace this, and to remove the valve-cover, the PCV first has to be unplugged. This is a rubber hose that attaches to the valve cover using a special pressure-release valve, much like a pressure cooker valve. Except mine wouldn’t budge. I tried with all my might, and finally it cracked in two. Bugger. All the year’s heat cycles had taken its toll. So I ordered a new one, and also the rubber grommet that seals it against the valve cover. This was a good decision, because when I tried to take out the old grommet it also simply tore up into pieces which I had to fish out of the valve cover chamber. What I didn’t expect to find though, was paper. Someone had stuffed a bunch of paper into the hole of the PCV at some point (probably to block it off, for some reason?). It was hardened and crusty from the old oil, but it came out easily enough. It could also have been old excess gasket-maker. Never use that on your valve cover. Never.

What was left of the PCV grommet.

Then suddenly my power steering starts becoming dodgy and stops working. The belt was slipping at first and then it came off. I put it back but it just came off again. Turned out, the air conditioning pump was completely loose and any strain on the belt would just lift it up, which slackened the belt. The reason was that a bolt was missing. There is a second bolt at the rear of the mounting bracket which was half-way undone, and this was all that was holding it in place. At first I thought this was a bolt similar to the swivel bolt that the power steering pump uses to adjust its position in order to set the belt tension correctly. It was difficult to confirm though, as I could not find any reference on the EPCs about the air conditioning pump mountings. It wasn’t the same. In fact, the missing bolt was not specific to the air conditioning at all. It was an oil pump bolt that also happens to hold and secure the air-con pump bracket in place, if air-con is fitted. And it’s an 8x1.25mm thread bolt, so I could not find any local supplier that could assist. A scrapyard in the UK and a week’s wait later, and I had the correct bolt. But it didn’t tighten enough. Clearly I (or someone before me) had stripped this hole’s thread in the past. So I just put on some Locktite and will hope for the best.

What was funny, however, was that I found two stray bolts between the air-con pump and it’s mounting bracket. It proved a real nuisance getting them out of there. Perhaps the air-con pump had been removed at one point, and a careless mechanic put the bolts in the bracket for safe-keeping later, and put the pump back right on top of them. Still, I now have two very large bolts extra.

I've encircled the tip of the one bolt where it was visible between the pump and the bracket. Oh, and all the dust too.

If you recall a few posts back when I refurbished my rear calipers, how big of a success that was. Well, unfortunately I wasn’t so lucky this time. My parking brake light started coming on intermittently again as a low fluid warning (this lesson I had learnt, right?). After a few top-ups and cleanups and wipe downs, it was clear that my master brake cylinder was leaking. But additionally, the grommet rubbers sealing the fluid reservoir was also leaking?!? The shelf against the firewall was pretty much covered in fluid by now. Taking it all apart is not trivial. The hard-line nuts are tight and you struggle for space with the spanner. The booster however is a particular royal pain in the ass to remove. The four nuts on the inside in the pedal box has so very little access that only my small ¼’’ socket wrench could fit somewhat, always at an angle on the nuts (so very easy to strip them), and then it could only ever turn for like 15 degrees or less. Don’t even attempt a spanner (ratchet or otherwise). And you’re upside down on your back brewing a headache. I read multiple forum posts about how guys found it easier to just remove their dashboards completely instead (especially the LHD cars). I had removed my steering wheel to get in there properly. And once those nuts are undone, you still can’t get it out because the fuse box and the thickest part of the loom is in the way, and the throttle cable and it’s bracket, and the hard-lines and the pressure regulator block… Sometimes I think neurosurgeons have an easier time.

The booster, upside down.

The booster looks worse than it is. There’s no moisture on its rubbers, and the boot around the actuator that attaches to the pedal is in very good condition still. I did clean it up and put a rattle can onto it.

So fast forward a few weeks and I’m prepping for spraying that shelf and part of the firewall. It was completely rusted out and there was a lot of cleaning up to do. The rust treatment (I used N1S1) worked very well, and the color coats and clear coat came out all right for my first time ever using a spray gun. It’s not an area that’s immediately visible, but I wanted to treat it properly regardless.

Before and after cleanup.
Wrapping, prepping and painting.

I had the master cylinder refurbished, but it still leaked after that from below the reservoir. The brake and clutch people said they reckon my original reservoir could possibly be compromised, and they dug out a spare reservoir from their parts cache; they believed the grommets were good.

But it didn’t work. I fitted it all back, the booster took a few tries because it is really hard to get it back in again, and because I forgot the dust gasket at first. It’s also easier to fit the regulator block first and secure its hard-lines and then to fit the master cylinder - something I’ll remember when I have to disassemble in the future. But after bleeding there was a puddle of brake fluid on the shelf again, ruining the paint job almost completely.

At this point I was pretty fed up and dejected, but my one friend got hold of those grommets for me and we replaced them. Do you see the irony here? I replace the grommet of the PCV right off the bat, but failed to do so with the master cylinder reservoir. Hey ho.

Pulling out the reservoir from the master cylinder is a really hard thing to do. My forearms still ache three days later. But with the new grommets there is no more leaking. We also had to swap out the fluid level switch from my original reservoir into the new one. At the moment there’s quite a bit of travel on the brake pedal, but the car stops good. I guess I’m just used to the CX-5 pedal now again, but we’ll do another round of bleeding sometime.