How To: Restoration of Ford M8 armoured car US Ordnance number 7373

[Big D]

Hi all,

I have finally got some brakes on the M8. In my last update I mentioned that after rotating the brake backing plates and bleeding all wheel cylinders I still had a slightly soft pedal. I clamped off all the axles again and individually checked them. I found that when I released the front and intermediate axles, the pedal was still firm but when I released the rear axle, I had a spongey pedal. Bugger! This axle was the first one I did with my new method so maybe my technique was not that good.

I was initially a bit reluctant to remove everything from that axle again and so I pumped up the pressure bleeder and bled off the bleeders I had fitted into the Tee connections. I then bled off the wheel cylinders. The fluid was clear with no signs of air. It was bugging me and I wasn’t happy so I decided to strip the hubs again. I rotated the backing plates and bled again and sure enough I got more air out of two of the cylinders. Not a lot like before, but it was there. A test of the pedal showed that it was firm like the others. If anyone is thinking about bleeding their brakes in this way, I can tell you while the process looks a bit daunting when you think about it, it is only about two hours to do a complete axle including bleeding.

This process confirmed for me with the Raybestos modification to the wheel cylinders, bleeding off the wheel cylinders when they are in the standard position is a complete waste of time. It has also shown that bleeding off the bleeders I put in the Tee connections is only useful to prevent air going into the wheel cylinders. It won’t remove air from the cylinders themselves. That air will remain stuck under the cups until you put the wheel cylinder in a rotated position where air can come out from under the cup. I think if I had to do a complete brake set up again, I might even replace the solid brake lines on the axles with flexible lines. This would make the bleeding process even easier.

Anyway, I feel like I can move forward again now after the last few months of frustrations with the wheel cylinders. I still have a little tweaking to do though. I fired up the engine today and tested the brake pedal to see if the Hydrovac is working. There was no discernible drop in the pedal on start up so I will check the vacuum connections. Maybe I haven't got something quite right there.

Next up, I started preparing the rear floor and engine covers for fitting. I left some bullet holes in the engine covers. That may not be to everyone’s taste but I figure they are all part of the vehicle’s history and they will be a good talking point. I’ll fit the engine covers once the guys are back working next door and I can use the fork hoist.

The floor is made from sheet metal that I cut, folded and welded. I also bolted a bit of box section to it to strengthen it a bit. I made the rear section so that it slides under the intermediate section. It is a slightly awkward thing to fit but I figure that if I have to remove any floor section it is more likely to be the intermediate section.

The floor section seems to fit nicely but I should have made the rear holes slightly bigger in diameter as with a couple of coats of paint on them, the bolts are a bit of a snug fit when trying to line the holes up with the nuts I welded onto the back panel.

That’s it for this year. Merry Xmas and a happy New Year to you.

Cheers
Darryl

[Big D]

More photos.

[Lynn Eades]

Well Darryl, that was a wee hurdle to get over. Glad it was you doing it. Well done!
Have a great Christmas!

[Big D]

Hi Lynn,

It was certainly a mission. Over the last few weeks I have also rebuilt the brakes on the scout car. They had been sleeved by the previous owner and just needed a clean up.

I used the pressure bleeder on that and I had the brakes done in about 20 minutes. Quite a difference when you have a horizontally mounted wheel cylinder.....

Merry Xmas to you to!

[Brian Butt]

Thanks Darryl for posting all the lessons you've learned. I just dropped off all 12 wheel cylinders and master cylinder to have stainless sleeves installed. We are sticking with the original cylinders, so hopefully we won't have as much trouble. But if we do, thanks to you, we will know what to do.

[Big D]

Hi Brian

Hopefully lots of ideas for you. I'd be very interested to hear how you get on.

[Big D]

Hi all,

Happy New Year. Just a quick update to show the latest progress.

I have completed the floor now. Everything seemed to line up with the exception of one hole. Not sure what I did there but that is now corrected. I had considered fabricating small profiled strips to go across the joins in the floor like the original floor, but in the end didn’t think it was necessary. I guess these ridges were there to provide grip as well as strengthening the floor but I don’t see that as an issue with what this will be doing.

The grenade and flare boxes are now fitted. The inner part of the hull is certainly taking shape now.

I have fitted the front fenders. They certainly change the look of the vehicle. In keeping with the look of the rest of the vehicle, I just tidied these up rather than completely restoring them to ‘factory finish’. I guess the purists might prefer that everything was straight and dent free but I still want the vehicle to look like it has been used. It has been in a war…

Out of interest, how have other M8/M20 owners fitted their front fenders? Does the folded edge at the rear of the fender sit under the sponson edge or over it? The holes on mine do not line up at all well if I fit them with the folded edge sitting over the top of the sponson. The holes do line up a lot better but not perfect if I have them as per my photo. I have seen photos of them fitted both ways so was curious what everyone else’s was like.

Now that I have the tool lockers fitted, I am not happy about the placement of the latches on one of the repro lids. I will need to reposition the latch so I figured I would put some latches on that looked more like the originals. Does anyone have a source for a latch that looks correct, or have originals by chance?

That is all.