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

[Big D]

More photos.

[Mike K]

hi Darryl

My neighbour has had problems with modern replacement imperial size brake rubber cups ( Made in Spain ) . The old original cups had a wider sealing lip compared to the modern replacements which are a bit of a bodge. PBR cups were pretty good but they are not easy to find these days. A good brake place is TRADE Brakes http://www.tradebrake.com.au/ they are very good with older vehicles and even have the old style lining rivets. Don't know what size your cylinders are but old stock PBR stuff turns up on EBAY sometimes. https://www.ebay.com.au/itm/3-PBR-Cy...kAAOSwk~pegcS3

[Big D]

Hi Mike,

Thanks for the reply. I thought after writing that last update that the new cups I had made, were actually made to fit the sleeve bores so they must be a match to that diameter. That sort of rules out the idea that the bores are fractionally too big as those cups were matched to them. As you say, maybe they don't seal as well as the ones with the older material. I'm not sure. It seems strange. The brakes aren't rocket science so I am a bit baffled by the whole thing.

[Mike K]

Measure the pistons with a micrometer maybe and the bores ?

[Andrew Rowe]

Hi Big D, can you post a pic of the ammeter you are after, may have something laying about, Cheers Andrew.

[Big D]

Hi Mike

Yes, I have sent the cylinders to the brake guy and he will do that. I don't trust my calipers.

Hi Andrew

It looks like this but it is a special Ammeter designed to work across a shunt. I can give you a part number if that helps.

[Big D]

Hi all,

Amongst other projects this week, I’ve done a bit more tinkering with different things on the M8.

I started up the engine again a week or so ago. It hasn’t run for nearly two months but started up almost immediately. I think the fuel pump on it is working very well. It was the first time I had the engine running since I fitted the exhaust system on it and sitting in the driver seat, I wasn’t sure it was running initially as the engine was very quiet. Here is another video: https://youtu.be/b6F-Bt4FQ_4

I had left the drive shafts off so I did some testing with the clutch and the gearbox. The clutch is definitely working well and while initially I was able to move through some of the gears, I found I was getting some binding and changing back from reverse into neutral was very tight.
I isolated the problem to the remote linkages, not the transmission. I had fabricated the longer of the two shafts that run between the transmission and the transmission control housing. Although I had the length of the long rod correct, the mounting hole spacing for the universal joint was out by a few mm. After drilling some new holes I put it all back together again and the transmission now shifts smoothly. I used some fairly sturdy pipe for this rather than solid rod. It seems sturdy enough so will see how that goes.

I ran the engine again and shifted through all the gears. It does shift very smoothly but the hydraulic clutch will take some getting used to. It just has a completely different feel to what I’m used to. Reverse gear does sound rumbly but I guess that is the cut of the gears?

Since that testing, I’ve fitted all the driveshafts ready for my road test. I was missing the little cap/cover that locks the universal joint bearing caps in place. After a bit of searching, I found some at a local scrap dealers. Interestingly, these are the same size as the covers that go in the hull above the sponsons for access to the tubing and wiring that runs through the channels on the sides of the vehicle. I have a couple of spares if anyone needs these.

I picked up a couple of M8 wheels a while back so I had the old run flat tyres removed and the wheels blasted and painted. I will swap these out with the two Scout Car/Half track wheels I currently have on the M8.

I spoke to my brake guy today. He has been working on the wheel cylinders I sent him. In his testing, he couldn’t fault one of the cylinders (!!) but does believe that the other one is leaking between the sleeve and the cylinder. He is going to press this sleeve out and fit a new one. Hopefully that will fix that one. He agreed with you guys in the US that the kits with the full cup and new pistons (the GMC type kits) are the way to go, so my plan going forward is to fit these new kits to each cylinder, bleed the system and monitor each wheel cylinder. If the cylinder develops a leak, I’ll send it back to the brake guy so he can redo the sleeve. It’s a lot of work, but I can’t see another way to progress things and it should all be for the best with the new pistons. That’s the plan, anyway….

A couple of other jobs I’ve been working on are a bridge weight sign and the turret ring indexing. Anthony from Axeholme Signs came to the party again and supplied me with a paint mask for the bridge weight sign and decals for the turret ring markings. The turret ring markings take some time to do but they do give a very nice result. Having the covers out of the vehicle is the way to do it. I'd say it would be a bit awkward doing it with them fitted around the turret.

That is all for this week…