Chevrolet C8

[Richard Nixon]

Good afternoon,

Thanks for letting me join, I have been very impressed with the knowledge and friendliness of this forum!
I have just bought this C8 from Ed Sayer, which was advertised on here and milweb. Bizarrely I looked at this last year at War and Peace, when R&Rs were selling it. Ed beat me to it, since then he’s done lots of work but has had to let it go due to work commitments.
It doesn’t need much to finish, mostly mechanical work to get it to a rolling restoration from there on.
After a brief assessment yesterday it needs the following done;
Brakes, no hydraulic pressure - possibly leaking rear cylinder. Hand brake is good.
Slight leak on water pump, I think that’s where it’s coming from!
Carb refurbish- feels like main jet is blocked. Ticks over fine but won’t pull when throttle is opened.
Few other bits and pieces, finish off the body and cab.

The first photo was when I saw it 118 months ago.

I dare say I’ll be asking loads of questions, so bare with me!!

[Richard Nixon]

Oops! I meant 18 months ago when I saw it first!!

[Hanno Spoelstra]

Hello Richard,

Glad to see you signed up for MLU. We have been keeping track of that C8, so it is great to have it's new owner as a member on our forum - welcome!

There are several C8 owners on here, so fire away with your questions and keep feeding us your updates with photos, please.

Thanks,
Hanno

[Richard Nixon]

Thanks Hanno, I'll keep you all posted! Once I have it driving and stopping ok, it will become a rolling restoration. My aim is to get it into desert trim, possibly as a signals truck, not sure exactly yet. The priority is to get it driving and stopping!!

[Richard Farrant]

Originally Posted by Richard Nixon

Thanks for letting me join, I have been very impressed with the knowledge and friendliness of this forum!
I have just bought this C8 from Ed Sayer, which was advertised on here and milweb. Bizarrely I looked at this last year at War and Peace, when R&Rs were selling it. Ed beat me to it, since then he’s done lots of work but has had to let it go due to work commitments.

Hi Richard,
I saw this on RR Services stand last year and thought there was something familiar about it, then later I met an old acquaintance and I think he told me he once owned it, possibly 20 or more years ago.

regards, Richard

[Phil Waterman]

Hi Richard

Hope you enjoy your new CMP and wish you many happy years of driving it.
Now as to your list of faults-

"After a brief assessment yesterday it needs the following done;
Brakes, no hydraulic pressure - possibly leaking rear cylinder. Hand brake is good.
Slight leak on water pump, I think that’s where it’s coming from!
Carb refurbish- feels like main jet is blocked. Ticks over fine but won’t pull when throttle is opened."

Couple of thought based on a fair number years with these beasties

Brake system, it it has original or NOS brake cylinders that have not been sleeved you might consider having them sleeved once you find the source of the problem. With owning 3 CMPs I have found that sleeving is a once and done approach to this problem. Unsleeved cylinders are good for 4-5 years before the water in the brake fluid will pit them. Some of my trucks are now coming up on 30 years without the cylinders having to be touched other than to replace the rubber parts every 10 years.

Water pump leak- try real hard to id the location of the leak is it coming from the drain hole in the housing? Or is it leaking around the hose connection point. Pat 12s it is hard to get your head in there to actually see but try with a mirror. Also it may be just a gasket.

Carb - Before you do anything to the carb how old is the gas. The modern gas in the US goes off in 3-4 months and runs like garbage. Have learned to hold off on trying to find power related problems until I dump new gas in the tank and run the engine long enough that I know it is getting fresh fuel to the Carb. Also check your air filter, Pattern 12s have a peculiar problem the placement of the airfilter can let water drip into the oil bath raising the level of the fluid in the filter so that engine has trouble breathing.

Even with rubber gasket at the top edge of the hood mine decided to add an inch of water to the filter. Truck would start but not pull well, like driving with the choke pulled out. This was from one rain storm, over night at a Club Event.

Another thought on the carb would be to put a vacuum gauge on and see what sort of vacuum it is pulling.

Again wish you many happy years of driving.

Cheers Phil

[Pete Ashby]

Very nice Richard that looks like an excellent buy.

Interesting to see you have a Ford bonnet (note the raised pressing for the Ford rad cap in the center front ) the Chevrolet produced version was flat.

There was a short period in 12 cab Chevrolet production when Ford bonnets were fitted this can be seen in period photos. I can't remember ever seeing an explanation for this does anyone know the answer? my old C15A 12 cab had a Ford bonnet and several other restored 12 cabs show the same feature.
Looking forward to following following your trucks progress lots of photos please.
regards
Pete

[Richard Farrant]

I am certain this is the one, here seen at Duxford in 1981 with the guy who bought it for restoration.

[Mike K]

Great to have another C8 on this forum. And a rising of Phoenix from the ashes , 1981.

Does it have a repro body ? I have the drawings taken off the Nick Bullock C8. If you need anything, let me know.

I agree with Phil have the brake cylinders sleeved in stainless steel. A long lasting solution .

Does it have the original carby ? The Carter is a over complicated example of engineering !

I had ongoing problems with leaky water pumps until I rebuilt one , fitting a modern ceramic seal . No leaks anymore !

[cletrac (RIP)]

I'd say the box is a repro. It doesn't look quite right. I have an original for comparison.

[Richard Nixon]

Originally Posted by Phil Waterman

Brake system, it it has original or NOS brake cylinders that have not been sleeved you might consider having them sleeved once you find the source of the problem. With owning 3 CMPs I have found that sleeving is a once and done approach to this problem. Unsleeved cylinders are good for 4-5 years before the water in the brake fluid will pit them. Some of my trucks are now coming up on 30 years without the cylinders having to be touched other than to replace the rubber parts every 10 years.

Water pump leak- try real hard to id the location of the leak is it coming from the drain hole in the housing? Or is it leaking around the hose connection point. Pat 12s it is hard to get your head in there to actually see but try with a mirror. Also it may be just a gasket.

Carb - Before you do anything to the carb how old is the gas. The modern gas in the US goes off in 3-4 months and runs like garbage. Have learned to hold off on trying to find power related problems until I dump new gas in the tank and run the engine long enough that I know it is getting fresh fuel to the Carb. Also check your air filter, Pattern 12s have a peculiar problem the placement of the airfilter can let water drip into the oil bath raising the level of the fluid in the filter so that engine has trouble breathing.

Even with rubber gasket at the top edge of the hood mine decided to add an inch of water to the filter. Truck would start but not pull well, like driving with the choke pulled out. This was from one rain storm, over night at a Club Event.

Another thought on the carb would be to put a vacuum gauge on and see what sort of vacuum it is pulling.

Many thanks for your reply, I'm new to Chevrolets so will take all the advice I can get!

I think sleeving the brakes is the way to go, if they havent been done already. I'll need to find someone to do it. I need to get into the drum and have a look.

The water leak is very hard to see where its coming from. I managed to nip up a couple of bolts, it seemed to make it worse!! Might have just disturbed something, however after running it up for a bit the leak has stopped. I noticed in the manual I have, that there is a drain hole. Good advice about using a mirror! I have a used water pump that needs refurbishing, I may got down that route. But as you say, look for the source (probably easier to find the source of the Nile!!)

The carb issue was identified by the previous owner - he 'borrowed' a carb off a friends truck, and he said it ran fine. Hence the thinking it is carb related. I have a spare later Rochester carb, I'll look to clean that up and refurbish it, put that on and see if it makes a difference. I have a refurb kit for the Carter W-1 thats on the Chev at the moment and get that done. The only other thing I noticed was a couple of big dents in the exhaust, on the down pipe, quite big creases. That will certainly have an effect on exiting gasses and increase back pressure.

I shall have a look at the air cleaner - an interesting problem!!

Thanks for the advice!

[Richard Nixon]

Originally Posted by Mike Kelly

Great to have another C8 on this forum. And a rising of Phoenix from the ashes , 1981.

Does it have a repro body ? I have the drawings taken off the Nick Bullock C8. If you need anything, let me know.

I agree with Phil have the brake cylinders sleeved in stainless steel. A long lasting solution .

Does it have the original carby ? The Carter is a over complicated example of engineering !

I had ongoing problems with leaky water pumps until I rebuilt one , fitting a modern ceramic seal . No leaks anymore !

The body looks like it has been either significantly restored, or a repro. The sides are very straight, indicating they have been replaced. The front stowage bins have had some significant repairs/panels replaced. If the truck is the one from the 1981 photo, it clearly has had the body replaced.

It has the Carter carb - I will refurb it, also have a Rochester carb to try.

The ceramic seal on water pump sounds like a good idea, where did you get it from?

Cheers
Richard

[Richard Nixon]

Originally Posted by Richard Farrant

I am certain this is the one, here seen at Duxford in 1981 with the guy who bought it for restoration.

Wow! Wouldn't that be amazing if it is the same truck? Cant see any registration marks on the photo.
I spoke to Kerry at R&Rs, he said that it came out of an auction last year at RAF Hendon museum. I don't have any more details at moment. I'm just around the corner from R&Rs so will pop in and see Kerry and hopefully he may have more details.

[Richard Nixon]

Originally Posted by cletrac

I'd say the box is a repro. It doesn't look quite right. I have an original for comparison.

Certainly it has had some significant work, especially the sides - so straight! Would be interesting to compare your body to this one. Do you have any photos you can post or point me to on here?

I would like to put hoops and canvass on the back, but priority is to get it running and stopping!

[Richard Nixon]

Originally Posted by Pete Ashby

Very nice Richard that looks like an excellent buy.

Interesting to see you have a Ford bonnet (note the raised pressing for the Ford rad cap in the center front ) the Chevrolet produced version was flat.

There was a short period in 12 cab Chevrolet production when Ford bonnets were fitted this can be seen in period photos. I can't remember ever seeing an explanation for this does anyone know the answer? my old C15A 12 cab had a Ford bonnet and several other restored 12 cabs show the same feature.
Looking forward to following following your trucks progress lots of photos please.
regards
Pete

I noticed the 'bulge' yesterday - the radiator filler neck bares no relation to the bulge, now I know why! If it was the truck in the 1981 photo, it certainly had the Ford bonnet back then!

[Mike K]

hi Richard

The Rochester would be a better carby . The 216 version has the smaller throttle bore. The 235 version seems to be more common over here , it has the larger throttle bore.

There is a weakness in the C8 drive train, the uni joint just behind the gearbox tends to fail. The uni joint is inside the round sphere , it drives the shaft inside the torque tube.

Do a search on this forum for C8 .

The front wings on your C8 look a little odd , sort of like somebody has made them in the back yard ! if you can find them, the wider wings from the larger 15cwt or 30cwt or 3 tonners will fit the C8 . You must narrow/cut the wider wings down , make them narrower, that's what the factory did ! The 13" wheels do appear to be "out of scale" under those huge long wings !

[Richard Farrant]

Originally Posted by Richard Nixon

Wow! Wouldn't that be amazing if it is the same truck? Cant see any registration marks on the photo.
I spoke to Kerry at R&Rs, he said that it came out of an auction last year at RAF Hendon museum. I don't have any more details at moment. I'm just around the corner from R&Rs so will pop in and see Kerry and hopefully he may have more details.

Hi Richard
I have just sent you a Private Message on here.

Regards Richard

[Richard Nixon]

Originally Posted by Mike Kelly

hi Richard

The Rochester would be a better carby . The 216 version has the smaller throttle bore. The 235 version seems to be more common over here , it has the larger throttle bore.

There is a weakness in the C8 drive train, the uni joint just behind the gearbox tends to fail. The uni joint is inside the round sphere , it drives the shaft inside the torque tube.

Do a search on this forum for C8 .

The front wings on your C8 look a little odd , sort of like somebody has made them in the back yard ! if you can find them, the wider wings from the larger 15cwt or 30cwt or 3 tonners will fit the C8 . You must narrow/cut the wider wings down , make them narrower, that's what the factory did ! The 13" wheels do appear to be "out of scale" under those huge long wings !

Hi Mike,

The Rochester carb is off a 216 of slightly later vintage. I'm going to refurb it and use it until I get the carter done. I need to be able to keep the C8 mobile while I do the work as I am limited on space and have to move it around.

I have heard about the universal joint - is there anything I can do to help its longevity?

The wings are wider than the rest of the truck! I thought they looked a little odd compared to the wheels too. I'm not familiar with CMP vehicles at all, so I wouldnt have known if they were right or wrong. The proportions dont look quite 'right'. They've certainly been on there a long while looking at the rust and the fixings on the brackets holding the wings. That will be something to look out for in the future. One good thing is that if the front end goes through a gap, the rest will too!

Thanks
Richard

[cletrac (RIP)]

Check out this thread.
You'll find lots of useful info here.

[Richard Nixon]

Originally Posted by cletrac

Check out this thread.
You'll find lots of useful info here.

Thanks David, with the posts Hanno provided earlier in this thread and the link you have given me, I've got quite a bit of history to my C8 already!
This forum is pretty amazing! Thanks everyone!

[Alex van de Wetering]

Richard,

Welcome to the forum and congrats on the purchase of your C8! Lovely truck!

Pattern 12s have a peculiar problem the placement of the airfilter can let water drip into the oil bath raising the level of the fluid in the filter so that engine has trouble breathing.

Once again....a vey valuble piece of info, Phil! I have to check if that's also the case with an 11cab....even though that has rain gutters along the edge of the engine cover.

Alex

[Phil Waterman]

Originally Posted by Alex van de Wetering

........
Once again....a vey valuble piece of info, Phil! I have to check if that's also the case with an 11cab....even though that has rain gutters along the edge of the engine cover.

Alex

Alex you make me wonder do any Pat 12s have the little gutter under the hood at the windscreen edge like the Pat 13s?

I agree good to see another CMP being enjoyed by new owner, keep us posted Richard.

Cheers Phil

[Pete Ashby]

Phil, my C15A 12 cab had a gutter fitted it was angled slightly down each side from the center line of the scuttle and fixed by two tabs that were held in place to the scuttle (under the webbing strip) with counter sunk machine screws I'm not sure if I have any photos of it I'll check

Pete

[Pete Ashby]

Just checked and I don't have a photo of the engine by of my old C15A, however I checked the well known factory photos (below) and there is certainly no gutter shown there.


Perhaps it was a field modification by CREME or maybe only REME just on trucks issued to the British, it was a pain really as it used to interfere with the hood hinges which made me think it was an addition rather than a factory fit but then 11 and 12 cabs are such a dogs breakfast of drawing board design changes and on line modifications that you can never be sure

Pete

[Richard Nixon]

Did a bit of work today, mostly finding my way around the truck. Here’s the engine rebuild plate, all standard in October 1945! How can I decode the plate to find out about where it was overhauled?

[Richard Nixon]

Originally Posted by Phil Waterman

Hi Richard

Carb - Before you do anything to the carb how old is the gas. The modern gas in the US goes off in 3-4 months and runs like garbage. Have learned to hold off on trying to find power related problems until I dump new gas in the tank and run the engine long enough that I know it is getting fresh fuel to the Carb. Also check your air filter, Pattern 12s have a peculiar problem the placement of the airfilter can let water drip into the oil bath raising the level of the fluid in the filter so that engine has trouble breathing.

Even with rubber gasket at the top edge of the hood mine decided to add an inch of water to the filter. Truck would start but not pull well, like driving with the choke pulled out. This was from one rain storm, over night at a Club Event.



Cheers Phil

I’ve had the air filter off and yes there was a bit of water in the bath. Small puddle on top of the filter leaking exactly as you said!But not enough to cause the issue. I ran it with out the filter and it still dies when opening it up. The fuel is new so I’ll end up refurbishing the carb I think.

[Richard Nixon]

I’ve started a blog on Facebook, if any of you are interested. I’ll make regular updates on this thread too!
Thanks for all the advice so far! It’s much appreciated.

https://www.facebook.com/c8tom/posts/1507947082594003

[Richard Nixon]

Not done a great deal on the C8 as work and Christmas got in the way. But had a spare bit of time and looked at the rear wheel cylinder that was leaking. I was suprised to see the rear cylinder was a 1 1/4 inch - I was expecting either 1 3/8 or 1 1/2 inch. Certainly the parts lists that I have gave that impression. However looking at LWD parts they list a 1 1/4 inch rear Cylinder for a C8A. Thankfully I have the 1 1/4 in stock - thanks to Pete Ashby! I'll be fitting this for the time being as I need to move the C8 and need some brakes! But should they be 1 3/8 inch?

The other little job turned out to be a 'mare! I fitted the rear light lenses, all good until I smelt burning. The tail light had started to melt! I realised the error of my ways - a 12v conversion means the bulbs are much hotter!! I challenged my lad to make me some new red lenses using a laser cutter. He bought them home today, absolutely brilliant! He's done a superb job. I've decided to used LED bulbs in the rear lights as they run much cooler. If anyone else needs red lenses for their rubbolites let me know, my lad, Zac, can make them.

[Richard Nixon]

Quick update on where I am with the C8.

Rebuilt the Carter carb - the accelerator pump leather washer had degraded and was the source of the issues. It now revs properly.
Had few ignition issues, so went to put new capacitor in and gap the points. Blooming heck!! What a job on a Cab 12!!! Never again - I've gone the electronic ignition route (Jolley Engineering kit). Fit and Forget! Much better pick up, smoother and no more cursing at the points!

There's a couple of oil leaks to sort out from around the sump area - cant quite see exactly where its coming from. Not bad, I guess its like the Land Rover empty oil warning system - when it stops dripping its time to fill it up!

While I'm here, gear box and rear diff oil. The Drivers instruction manual states a Hypoid 90 for the rear diff and C600 or Hypoid 90 for the gearbox. Miller oils do a EP90 hypoid suitable for transmissions with brass and bronze components, which sounds OK. Many say not to use an EP oil, Morris do AG90 without ep additives, is this suitable for hypoid transmissions? Confused

Looking at making the hoops for the rear body. I'll search the forum again for some drawings (remember seeing them before on here).
Has anyone bought any (C8) canvas recently from John and Mary Worthing? I heard that they may now only supply for American trucks and jeeps.

My tyres are OK, but a couple of them are showing signs of perishing. An internet search has resulted in very little in way of 900x13s. Any UK suppliers for this size?

[Alex van de Wetering]

Hi Richard,

I bought a set of BKT tyres for my C8 last year, from Big tyres UK.
https://www.bigtyres.co.uk/

There is a whole thread on availabilty of 9.00x13 tyres here

Good question about the canvas; Just like you I also heard that both Allied forces, as well as Worthing, only do US canvas projects.....but, I haven't asked them personally!

Good job on the C8!
Alex