Exhaust
something resembling a blog, by Lewis Collard

Experiments within a project within a project

A Rover P5 3 Litre brake servo

This is my brake servo.

I removed it from the car as part of the "refurbish the brakes" subproject of the "financially ruinous Rover P5" project. It's a separate unit from the pedal-activated cylinder unlike it is on almost any other car, because Rover loved overcomplicating things back then.

The vacuum chamber (the large cylinder on the right) was half-full with brake fluid. As the name "vacuum" implies, there is not meant to be any fluid in there at all. That was quite the surprise when I took it apart, and also a surprise which caused me to lose a full set of clothing. There was little way the servo could have been functioning, and I suspect that aeration of the brake fluid would have caused the braking system to be minimally-functional even without the servo's assistance.

I suspected this seal may have been the problem:

A dodgy seal on the control piston on the P5's brake servo.

But, the unit was so ugly that I cannot say for sure that any single component was at fault. The photos you see here were after a blast of electrical contact cleaner (which is great for cleaning up anything that isn't an electrical contact).

Exploring the P5's servo internals.

I take a lot of photos in the course of doing things as reference for how things need to go back together. In the above one, you can see quite a lot of mank in the servo's internals.

Under other circumstances, I would have considered giving it a wire brush on the outside, a soak in petrol and a skim with very mild abrasives to clean the cylinders. But while I was ordering an electroplating kit for the various fasteners I have removed from the car, it seemed a good idea to order an electrolytic cleaning kit` as an experiment! As if I didn't have enough new things to learn...

Electrolytic cleaning is, in my head, electroplating in reverse. Rather than using an electric current to attract material onto a thing you want to plate, you operate it in reverse so an electric current attracts material away from a thing you want to clean.

It works quite well. In the process of working quite well, it turns the electrolyte (this is water mixed with powdered sodium carbonate) into the only thing I would like to drink less than brake fluid or Foster's.

What looks like a bucket of very scummy water

The exterior of the servo still required some love from a wire brush on the outside after the cleaning. The two bores feel very nice after the cleaning, so I will leave them be.

A P5 brake servo after electrolytic cleaning and some wire-brush action; it has scrubbed up well.

And the part that makes me happiest, is that the Girling wordmark is now visible!

The word "Girling", previously not visible, on my brake servo

And that...means that after two weekends I am half-way through rebuilding one of the components of one of the sub-projects of the P5.

Onwards!

I never really trusted folks who have to talk so loud

🎵
Well I don't need more guilt here in my life
How the hell is that supposed to help me find the light?
And I don't need you preaching at me day and night
About the way I look, the way I walk
The way I dress and the way I talk
There's something that you think you see like you've ever looked at me

You say you've got it figured out
And you seem so damn proud about it
I never really trusted folks who have to talk so loud

That ain't to say you never looked me in the eye
But lookin' isn't seein' when you just can't spare the time
Besides you're selling things I just don't feel like buying
Like guilt and pain
Fear and shame
Who to thank, and who to blame
A set of rules that's bound to keep the living out of life
Who to love and who to hate
What's too soon and what's too late
There's some test you have to pass before you feel the love of God

Well I don't need some fear of afterlife
How the hell is that supposed to help me find the light?
And I don't need you preaching at me day and night
About the things I do and the things I don't
What I will and what I won't
There's fire in your eyes sir, and it chills me to the bone

You say you've got it figured out
And you seem so damn proud about it
I never really trusted folks who have to talk so loud

So thanks a lot man, but I'll be moving on
Yours is a hateful sermon, and it takes too goddamned long
See, life is short and I'm gonna find mine searching for the light

🎵

A visit to the body filler mines of Norfolk

Video contains strong language.

And that, kids, is where your P38 comes from!

This was not an act of wanton destruction and savagery. I would be lying if I said I didn't enjoy it, but it was necessary, because my brother's 1963 Land Rover had, as my brother sagely observed, a lot of filler.

A near-centimeter-thick block of filler
Pictured: A lot of filler.

Some time before my brother bought this Land Rover in 2008, someone had tried to make its bodywork a bit smarter, with a lot of filler. I cannot say that this was a terrible idea, because it held up as well as a monstrous amount of filler could reasonably hold up.

It took my brother rolling the car onto its side some years ago to crack it severely, with some help from daily driving for years, three road trips to Africa, and one gentle road trip to China via Kazakhstan and Mongolia. Even then, as ugly as it was, it was not an MOT failure, until someone picked off some bits of it, and then it was an MOT failure because of an exposed sharp edge.

A somewhat less-straight panel, but not made of filler

So, with a lot of filler removed, and some help from a blowtorch, soap[1], and a selection of percussive persuasion tools, we had a straight panel again. I say "straight", though I actually mean "straight enough to be presentable on a battered Land Rover". I made sure that Alex was out of arms reach and did not have any power tools to hand when I said "that's straight enough, but do you know how we could make that panel absolutely perfect? If we got a lot of filler..."

Many other things were completed over the weekend, thanks to Alex's superhuman motivation. And also his ability to talk people out of whatever else they wanted to do and into helping him.

Me, watching a British Drift Championship livestream while working on the Land Rover.
But not even Alex can make me miss a British Drift Championship livestream...

I had other things to do with my current project-within-a-project on the P5 (more on this soon-ish), but after the filler-mining was complete of course I stayed up much longer than I was expecting to stay up, helping him wire in a pair of new horrifically-bright LED light bars, because Alex can talk toothpaste back into the tube...

LED light bars, with a useful comparison to the standard headlights

...which took us into the early hours of the morning, and all of that was definitely a good way to spend 14 hours!

Me, early hours of the morning

Thanks to Alex for the video and a couple of the pictures in this post.


[1] With very thin aluminium such as that of a Land Rover body panel, you mark the area you want to with ordinary soap. Heat that area with a blowtorch. When the soap turns black, it is at a temperature that is more-or-less optimal for percussive reshaping. :)

The little things

Page from the manual of a Rover P5, showing exactly what tools are needed for the job.

I love good documentation.

The Rover P5's workshop manual - the original one written by the engineers at Rover - is the best manual I have ever used. I especially enjoy that the manual sets out exactly what tools you will need including the sizes of spanners in the preface. This is the only workshop manual I have seen that does this, and it makes every job a tiny bit faster and a tiny bit more fun.

How many times did I work on the Mazda and read through a 20-step walkthrough and then in step 19 it says "use special tool, part number F-U, which is obviously completely unavailable for any amount of money to remove this delicate thing that will definitely break if you try to use cruder methods to remove it"?

Good documentation is important, and I believe in thanking people for good work even if I am late to their particular party. So, thank you, Rover engineers from 60 years ago. You did a fantastic job.

Cat, "I brought you a present" configuration

Guard Cat, with a very dead mouse in her mouth

Can't hate her for it. Mice love eating upholstery and wiring looms; maybe she's as critical to a car build as cats were in our ancient history when they enabled us to develop agriculture. So thanks Cat, but maybe don't bring that inside...