Rosie's return to glory

[TorqueHorse]

2 of 3 cracks not leaking
Proud to report that there is no water leaking from both of my repairs so far. Since I got the tank off, it rained a lot this week and I was able to harvest the rain water and fill and flush the tank a couple of times. I also watched a lot of Kayak repair videos and have been collecting odds and ends over the past few weeks to have supplies.

Today was nice and dry and though I was sick in bed yesterday, I got a bit of work in today. Here is my method. Drill some divots at the ends of the crack to keep it from going any further. Clean and sand the area and then I used the pretty basic screwdriver and propane welders torch to heat it up.

The tank is thick, so you can really sink the metal into the plastic to work it. I made a little stitch or staple like pattern with the head of the screw driver dow the crack. I think this both tacks the crack with the base tank material and creates more surface area for the repair material to bond into.

I layed in two layers of thick lid type plastic for the length of the crack. Then covered it all with a layer of milk jug plastic that was probably at least an inch wide to hopefully hold it all together.

Then tried the more convoluted geometry of the crack near the top.

Only got one layer on so far and think I'll go to the milk jug layer next since it doesn't leak and I think it needs more shear reinforcing over depth of penetration. After studying the tank more this week, I see that this crack happens where one of the straps comes up and there is still a lot of tank hanging out where I could imagine a not so well supported, sloshing around gallons of weight, could create a lot of stress at that connection point. But this crack is higher than the dreaded fuel filler pipe crack, so I don't think fuel ever even made it up here to leak out, so I'm not too concerned.

Still have the multiple cracks around the filler pipe neck. Have been building up my skill to deal with this mess of curves, and differing thicknesses of material

And I plugged in the fuel pump and fuel level float and turned the car to ON to test the float. I raised and lowered the float, but saw nothing change on the gauge at the dash. Maybe it fluttered a mm but I couldn't really tell since I was at the back of the car holding the float.

So, any ideas? Would the inertia switch need to be depressed to normal again to get a signal from the float? Is there some sort of circuit that made when the float and pump are sitting in liquid that isn't happening when I hold it in air? Or is it all so corroded that I need to clean it all and try again (or replace)?

[Rambo]

One question. Are your thick lid type plastics and milk bottle plastics compatible with petrol and the original tank material ?

[dapinky]

One question. Are your thick lid type plastics and milk bottle plastics compatible with petrol and the original tank material ?

I assume that the American ones are the same material as the UK ones - but certainly the UK ones are the same material as the tank, and are what I used for mine.......

.... it is possible to purchase 'welding sticks' of the correct fillers (there are many different types) in various colours.... but as the tank doesn't get seen, my repairs are green!

{all info provided to me by a motorcycle repair guy who does it for a living using lots of different 'plastics'.}

*The actual milk containers in the UK are a different material, but can be used as a 'top coat' cover if you wish to......

....oh, and if you want the same colour as the tank, the best bet is to nick the lid off your neighbours' wheelie bin

[Rambo]

TH - for peace of mind, are you going to pressure test your tank once all holes and cracks have been filled ? Or just rely on a tank full of water, gravity and a visual inspection ?

[GeoffSmith]

Couple questions though:
Does anyone know if the fuel level float sends info back to the gauge when the key is in ACC or ON position, without starting the car first? I'll plug it in to check before I put the tank back, but would be nice to know if I'd just run into a false negative.

Powered from the ignition supply. If the voltmeter is working, then so too should the fuel gauge.

[TorqueHorse]

@Geoff Thanks for the tip on the fuel gauge! Now to chase down if the fault is at the rheostat or the gauge.

@Rambo From section LG.1 "the tank is made from...high density polyethylene..." and fortunately right on the 6-pack can holders was printed that it is made from recycled HDPE, so I've been using mostly that batch of plastic from my collection. And yeah, I don't know in the UK, but here the milk jugs are also HDPE, so nice cheap score there and I feel pretty confident it will work.
I wasn't planning on doing a pressure test though since 1) there are so many orifices, I don't know how I'd plug them all to test, and 2) It is just the fuel line that is pressurized, not the tank, so I don't think I would learn much new. But I do plan on giving it the sudden kinetic impact test (i.e., kicking it) to see how the welds hold from all the bumps on the road


Still trying to source some replacement pads for the 4 I'm missing. Thinking I'll get a sheet of neoprene at thickness and cut it down. Now I'm running into all the scope creep too now that the wishbone is off. So much cleaning and resurfacing that is calling me. Could I stand putting a rusty part back on the car? I should get a principle around this to help keep me focused. If anyone has some that have helped them over the years, I'm all ears

[david924s]

Sounds like you have your work cut out for you and that's a big job to tackle but well done for getting on with it.

As to how far to go with the work I suppose it depends how quickly you want it back on the road, but if it was me anything I took off to do a job that needed doing I would clean, paint and or replace as it is much easier to do it while all in bits.

Just make a list of what you think needs doing and obviously add to it as you progress through but if you want to use it quickly then like I said I would stick to repairing/replacing what was broken or worn out and while anything was off the car or gave you better access clean and paint up the bits you can't normally get to. If you want to spend all Summer working on the car and money no object then the refurbishment is a big as your pockets but if it was me I would do what was necessary clean and paint what I had access to while in the air and use it through Summer, there is next Winter to do the nice to have bits.

[TorqueHorse]

Tank back in, but knocked hard

Thanks for the advice on how to approach the work. I've decided that I can wait, and I'm not putting rusty things back on, that I don't plan to fix in a future, scheduled rebuild, unless it is a doozy like the one which I cover at the end of this post. But to start, I finally got the tank back in this weekend. So three cracks total patched with melting and filler material. We will see how they hold.

I cleaned everything as best as I could and am pretty happy with the results. Those stainless steel straps really gave a satisfying shine. Took the sender with the rheostat apart and cleaned the connections and retweaked the spring angle. But the resistive surface is pretty worn, so using a multimeter I was able to see that it send signals back in the correct ohm range (for most positions of the float) but there are some spots where it loses connection, mostly just at all full, so I think I will know the difference. Was able to check that the gauge on the dash worked by grounding back the connection (= zero resistance) from what plugs into the sender and it all worked. Replaced the fuel filter and installed new vitron o-rings at both ends. Also checked the o-rings at the feed and return line connections, and the o-rings were in good shape, but also in reversed order from the WSM, which someone else noticed on theirs too. Fuel is now in the tank and reading is where I'd expect.

Hardest part was was getting the rear tank strap back on. Once the neoprene pads were on, it was a VERY snug fit to get back in. I had a helper for a period of time, but we just couldn't get the bolt to bite on the nut thread with the angle where the strap/nut ended up being with the tank in place. In the end, I did it by myself, by wedging wood blocks and a stool under the tank to compress it up and flush against the forward body. Then I also had a slender piece of wood that I also wedged, pushing the strap nut/connector up as close to the top of the cavity as I could. Basically instead of what we were doing with our arms while lying on the ground under the tank and getting tired and not keeping the strap still, the wood strip just did it better, with more force, and didn't move.

But as satisfying as that was, I am now caught up in the next problem, which sounds very expensive, if not unsolvable. Wanting to check if fuel pump was working, and if there were any leaks developing, I decided to start the engine, and see what we got. Just because I know you will ask, yes there is oil in it (to the full fill line when cold) but the timing belt is probably really old so I'm not doing more than driveway tests (plus it is up on jack stands so it isn't going anywhere anyway). No fuel leaks, yay. Rough idle, and ticking/knocking that sounds like rod knock to me, ugh . I swear the noise wasn't there when I got her, but guess I could have missed it. Now I haven't touched the timing, or the spark plugs, and I've heard people talk about the hydraulic tappets, but this doesn't sound like that to me.
Video of the offending noise https://photos.app.goo.gl/xmeDhfy9Mu28hEmK7
Would elanscan help me diagnose, or is this case closed, don't run it again and make it worse? Thanks folks.

[Brit-Car-Nut]

Sounds like a dry tappet to me...

You have decent oil pressure, so I am not thinking it is a rod bearing.

[esprit888]

I agree with John, I have a digital frequency isolator and it sounds very much like a dry lifter. As you’ll soon have the timing belt off anyway remove the cams, then remove clean and pump up the lifters.

[Rambo]

Sorry, can't comment on your engine problems but at least your alternator looks like its working correctly and providing charge to the battery. Unlike your boost gauge which should be at the bottom stop

PS My better half, who knows nothing about engines, said "that sounds rough"

[Kipperozzy]

Hello Torquehorse, sounds to me it’s not running on all cylinders, check the plugs to see if any are wet with petrol or burnt, and sort that, and/or injectors not firing and the knock may be easier to figure out but don’t rev it up much ....
Good luck

[Brit-Car-Nut]

If it is a bad/collapsed lifter, then that cylinder won't be performing as it should and it should be running less than smooth.

[muley]

Another possibility; although I'm not sure how it might happen ~ pistons hitting the valves if the timing belt was out of whack..

[robertverhey]

My tank was cracked in almost the same place as your third pic and I think it was because the straps were over-tightened. They should only be tightened enough to make the tank secure, and then the locknut nipped up to the first nut to prevent movement from there. Mine was tightened right up to the bodywork, which may have created distortion and a crack.

[david924s]

Does sound like a stuck tappet or tappets, I wouldn't run it anymore until you have had the top off to change the timing belt and can check the state of the cams, tappets etc. If it has been standing that long the oil has probably gone off and is not getting up to the top of the engine enough to fill the lifters, I would get the covers off and check the cams, tappets and oil ways, likely the lifters are full of dried up oil then take it from there depending what you find.

[NewLogik]

I have to agree with everyone on this. Definitely sounds like dry hydraulic lifters. On top of that, there's might be other things like sparkplugs and wires, timing, etc... that make it sound even worst, but I wouldn't expect a rod knocking to sound like this.

Keep going, you'll be happy to get the car back on the road at some point

[TorqueHorse]

Thanks all, I appreciate the tips, advice, and remote diagnosing You all were able to ward off the deep dread that I got when I heard it the first time. Plus there is that nice video BritCarNut has about cleaning the tappets, that it actually looks like a fun project.
@robertverhey Thanks, I'll be sure to do it that way when I put the tank back on because...
@Rambo, remember when you asked me if I was going to pressure test it, and I was like pffft?

This was like morning #3 after I had put the tank back on. The good news is that second time around, getting that thing off was a breeze. I can almost see how I could have finished the whole job in the WSM's 2.5hr allotted time.
So that is what I've been doing the past however long. Have been able to borrow a neighbor's compressor and found new leaks too. It has been slower to fix the welds too this time because of all the crap plastic that I have on there now, kind of obscures where the actual leak is, so I've had to spend more time really melting the areas. Just got done with my 3rd pressure test and there are still 1 or 2 niggling little dribbles somewhere around the filler neck. Got my weekend goal of finishing that and getting it back on there for good.
And I got a new rheostat from a slow boat purchase from last month, so now that tank is off anyway, I might try and perform surgery and replace the board in the sender unit. It was a 5 buck special from China and for a different car, but the Ohm range is the same, so I thought it would be good back up. As I'm typing this though, I'm remembering that the tank did get a reading well enough when I did have it on, so maybe I'll actually try and live with what I have before doing irreversible surgery. Plus, the start-up ignition takes a few tries and a bit of pumping the gas, so I might need to be replacing the fuel pump anyways...

Ok, so this is probably verboten here, but I'll share anyways. Since the paint is in such terrible condition as you know, Rosie will need a full respray. It seems like once you respray, you aren't in the upper resale price ranges anymore, so the cost of the paint is really for your own happiness. If that's the case, I feel like I have a bit more flexibility to try things. One idea I was playing with was going back to some of the original Peter Stevens concept art, which also reminded me a bit of the old Cortina styling.

Just really dynamic in how it ties into the rear light assembly. So here is a rough concept of how it might look on a real M100.

Could probably even do it in a vinyl wrap kind of way so the paint would still be Calypso if I ever wanted to revert. Anyways, I'm prepared for the bashing, but it was fun to take a break from the gas tank for a bit and play with something new.

[TorqueHorse]

Tank back in
If at first you don't succeed, try, try, try^50....again. In the end, I went with a clothes iron and some parchment paper to seal everything. The iron at max temp seemed just the right temp to get the patch plastic to a fluid temp, without it burning. I could let the iron heat up a patch and then really just lean on it to get it to flow into the cracks and create a wide enough surface area contact beyond the crack to hold it in place. After countless pressure cycles and days/weeks of the tank sitting full to find all the niggling pinpoint leak spots and patch them, I'm a lot more humble about calling something 'done' .
FYI, of what I tried over the months of doing this, the soldering iron seemed too hot and would often burn through, and the heated screwdriver took a lot of time, and couldn't get a big surface area. If I had (have?) to do it again, I might shell out for the HDPE welding tool, but let's hope it doesn't come to that.

Just for all the other stubborn folks out there without a helper, here is jury-rigged setup I had to hold the bottom of the back strap into place, so that I could screw it back together on my own.

With the tank back on, now I can proceed with more of the engine bay jobs. The first is really just cleaning it up to see more of where the problems are. And as you can see from all the deposits on the prongeron, there is no shortage of problem leaks. I'm also treating the rust on the ARB's and the left rear suspension I removed for the gas tank. Given their age, all the metal is looking good, with just surface rust and some paint flaking where it looks like stones have chipped it. All the bushings I've seen look really good too. More progress photos on the finishing of the suspension as they come. And probably some gory oil buildups before/after if I can get a decent camera angle.

While I was taking the prongeron off, one of the hardest bolts to get to was the right hand raft mounting under the right driveshaft. As you can see in the photo, the boot was laying down on it, preventing access. And while the boot is shot, I'm more worried about how it happened, because it seems as if it will hit the top of this bolt all the time. So is my geometry whack, or is the clearance really this tight normally?

[esprit888]

I have my RH drive shaft off right now and have had the boots replaced, i will be putting it back on in a day or so and will measure.