Dipped in green glass

[Nick Moore]

I'm copying the diff catch tank idea from my friend Rocky, who was one of the Subaru diff conversion pioneers. On his first few drives, he found the back of his Vitesse was getting covered in oil. The problem turned out to be the lack of a diff breather. The original Subaru rear cover had a breather in it, slightly fancier than Triumph's split pin but doing the same job. The cast alloy plates for mounting the diff to a Triumh chassis didn't have a breather, so the diff would pressurise and force oil out past the seals. Live and learn!

Rocky's solution was to take a pipe from the top of the diff into the boot, and have it vent into a catch tank so that any oil forced out wouldn't end up on the road or under the car. In theory, very little oil should be pumped out as the breather comes from the top of the diff plate. In practice, we'll see. It will be easy to see how much is being forced out, whether the amount remains constant and it will also make it easy peasy to top the diff up!

[Nick Moore]

Despite three visits by a mobile windscreen fitter, my GT still doesn't have a windscreen.

The first fitter found that the windscreen, made here in Australia by PGI, was too large. PGI ground it down slightly to exactly match the dimensions in their catalogue - for free, which was nice.

The second fitter took the screen back to the workshop to fit the trim to the rubber. It took them a couple of weeks but they a managed to get the strips in place. Yesterday the fitter came back, got the windscreen in, but found that PGI still hadn't trimmed the screen down far enough. In the process the stainless trim popped out again!

So, the windscreen is back at the workshop, where it will get ground down by another 3mm. Then they'll refit the trim again, and come back for Round Four.

It seems to be a combination of problems. Firstly, the windscreen has been poorly made. If I had an original Triumph windscreen, it would be the right size. But try shipping a windscreen around the world! You'd get something... Secondly, the rubber is aftermarket and although O'Briens Glass haven't criticised it, it may be causing problems. And thirdly, the design of the trim itself has the professionals almost beat. They've never worked on a Triumph before but as they say, it just doesn't need to be this hard.

Stay tuned for the next exciting episode in 'First Glass'!

[bob dunn]

I fitted my screen in an hour with a pair of steel toe capped boots . You might like the method, 1, take the laces out of the boots ,2, fit rubber to screen ,3, tie laces to each other ,4, fit laces to rubber with the knot at the top middle(the knot is out of the rubber),5,place assembly bottom edge on the bottom horizontal edge of aparture ,6,soap it all ,7, pull out the laces with a big friend leaning on the screen ,8,put laces back in boots ,9,spend two weeks wondering about the soapy smell.

[Nick Moore]

Yeah, I tried the string'n'shove method, to much amusement from the neighbours but no movement from the screen. Even with it firmly engaged at the bottom, it was too tall to fit under the folded over flange at the front of the roof. The fitter said it was a real bugger to force down further so that it could move back into the windscreen frame.

When it comes back next week it will be about 6mm smaller top to bottom. If that doesn't work I will buy a pair of Biggles goggles.

[bob dunn]

Do you have a dog , caus then you could get Doggles!!!

[bob dunn]

https://fbcdn-profile-a.akamai.....3493aff89e112386e529

[Nick Moore]

The discussion in the 'Brake Servo' thread about dual circuit brakes (Sorry , link no longer available) is very relevant to my Green Monster right now. In short, the brakes have been plumbed up as per US-1972 spec, but the rear brake circuit isn't working.

Background: US-spec 1972 GT6s, which mine was, had dual circuit brakes. They had a tandem master cylinder and a Pressure Differential Warning Assembly, which lit up a trouble light on the dashboard when one side started to leak. I've replicated this setup and added a servo for the front brakes. That's what Triumph did as well - the back brakes remained unboosted.

The front circuit seems to be working. The servo and calipers were easily bled, and there's some resistance in the pedal. The rear circuit isn't working though. There's some fluid in the rear line at the PDWA, but none at the rear of the car. I think the problem is in the master cylinder and the fluid has simply moved through under gravity. Oh, and the PDWA leaks - fortunately two pack paint is more resistant to brake fluid than lacquer 🤔

So I'm at a crossroads. I can persevere with the tandem setup or replace it with a simpler single circuit system. To fix the current setup, I'll have to strip and overhaul the pretty complicated tandem master cylinder and the PDWA. Both were New Old Stock as refurbishment kits are hard to find, especially for the PDWA. Just ask Wim. Even with that done, however, I'm still not sure that a boosted front and unboosted rear is a good idea. I have Canley's alloy 4-pot calipers and large discs up front and strongly suspect that the standard rear drums won't do much compared to boosted uprated front brakes.

The alternative is to change to a single circuit system, with the booster operating all the brakes, and no damned PDWA - in other words, change to a UK-spec system. The 'pro' is that it'll be cheaper, will eliminate potentially leaky components and will keep the rear brakes working proportionally to the fronts. The 'con' is that if the system leaks it'll loose all its fluid, just like my Herald (although that's never happened). As a backup, I could fit a low fluid level indicator to the master cylinder cap to warn if the system develops a leak. Something like this: http://www.carbuildersolutions.com/uk/brake-fluid-reservoir-cap

So, opinions: rebuild (again) the complicated and possibly poorly designed dual circuit system, or go single? Either way I want to keep the booster, as I like light brakes.

[booley]

I never knew the servo only boosted the front brakes...

stupid question: is the switch in the PDWA "centered"? If not, could be the reason why there is no fluid at the rear

[re5rotary]

Hi check that there is free play between the pushrod and the master cylinder piston. If there is no freeboard at the pedal then that can stop the rear circuit working as fluid can not get from the reservoir to the rear circuit part of the master cylinder

[Nick Moore]

Quoted from booley

stupid question: is the switch in the PDWA "centered"? If not, could be the reason why there is no fluid at the rear

Not a stupid question at all! It probably isn't centred - I've had a look but can't say I was convinced that the shuttle's depression was visible. And some people have suggested that some PDWAs act as an isolating valve. The cross-sections of mine seem to indicate that it doesn't, but I haven't pulled it apart to be sure. Yet.

Consulting Mr Google, it looks as though the master cylinder has two pistons, and just because the front one is free to move it doesn't mean that the rear one isn't stuck. That may be my problem. Even if I fix it though, it doesn't mean that the one-circuit-boosted brake system as I've built it will work well. Maybe I could fit a second booster for the rear brakes...

On a happier note, I just fitted a set of teflon leaf spring buttons, made by a guy named Ondrej in the Czech Republic. He's on eBay as 'Oakman-cz'. He sells them in both standard thickness and thicker for saggy springs. I'm happy with them

[re5rotary]

Mr Triumph boosted the front circuit only for a very good reason on the GT6, There is so much weight and weight transfer to the front of a GT6 under braking that the rears would just lock up as they are so lightly loaded. Your setup should work just fine if you can get the rear circuit bled

[WIMPUS]

Just seen that you are having trouble's with the valve 🤔
Maybe the seals where bad on it ?

I have now got it 2 times that the seals went, this seals that are in are still regular rubber.
But seem to still be good.

But i now do have got EPDM rubber seals, still not fitted them..
I had another old valve i got from a broken spitfire (where i got the engine/diff, door, driveshafts from).
I've now rebuild that with the new EPDM seals and seems they fit good, but when the valve leaks again it can just change the valve to the good one 🙂

Seems the valve is a bit different to mine ..

I also get your idea of making it to a single line system again.
I was thinking that also at one point, or just replacing the lines between master and brake union, so the valve could go away as i also have a new tandem master cylinder .

[Nick Moore]

Been fiddling some more. Some have said that the tandem system will never work properly, but I'll persevere a little longer before throwing in the towel. The PDWA's leak seems to be from a poorly made pipe flare. I have a couple of flaring tools but am not very good at making the flared ends. Some are OK, but this one isn't. A professionally re-flared pipe end should cure the leak.

Despite the master cylinder being new old stock, a thin layer of rust has formed in its reservoir, suggesting that the bores have been exposed to the air and rusted while in storage. My guess is that the rear piston has been gummed up with rust - the two pistons aren't  connected to each other except then the front one pushes the rear one. Just because the front one returns, doesn't mean the rear one will. I'll strip it down, inspect the seals and bores, and see what's what. Hopefully the bores will only need honing. It needs a 12mm Allen key to dismantle - and of course my set stopped at 10mm - so a 12mm key is on the way from eBay. To be continued...

On a happier note, the Teflon spring buttons are in. Some buttons are thicker than standard, making the rear of the car higher, but that's not the case here. She sits as low as before - not so low as to scrape on the ground, but low enough to make getting out amusing for onlookers! The spring leaves were slathered with grease before reassembly - fun job, that.

[byakk0]

not sure about down under, but there are places in the States that will bore and sleeve your master cylinder with a brass sleeve.

[Nick Moore]

Stripping the tandem master cylinder confirmed what the rust powder in the reservoir had hinted at - the bore has rusted where the rear seal sat for forty years. You can see the rust in the second photo (damned hard to take a photo of this, I ended up using a macro lens and shallow depth of focus). I think the pits are too deep to cure with a honing stone, so it needs resleeving. The front and rear sections are different diameters, making it a tricky and no doubt expensive job.

Moral - as much as we bitch about reproduction items being crap, don't assume that NOS parts will be the same quality as brand new after decades on a shelf.

[Nick Moore]

The windscreen is in! It only took two years and four visits from the mobile fitters. Why? Because the locally manufactured glass was too damned big, and getting a windscreen imported intact would have been expensive and risky.

The windscreen was made by PGI here in Brisbane, and supplied and fitted by O'Brien's Glass. O'Briens had to machine 3mm off all around even after I'd had PGI machine it down, and they also made a special tool to fit the trim to the rubber. After all that they still only charged me the standard one-visit fee, so they definitely deserve a free plug here. Rob the fitter brought an assistant so that he could see how old-style rubber seals screens are fitted. Here's how he did it:

First, the trim was fitted to the seal, and then the glass was fitted to the seal. That was done back at their workshop. The windscreen was fitted to the car top-side first. (I remember fitting the Herald's windscreen the other way around - bottom side in first, but the roof lip got in the way here). I had to remove the dash crash pad so that they could pull the string through along the bottom edge of the windscreen. I'll find all the nuts later... And it was sealed with heaps of black mastic. Their apprentice lost one stainless clip (fitting my trim was punishment detail for newbies), so O'Briens are making two new ones free of charge - they'll be here next week.

Oh, and this isn't the hardest one Rob has done. P5 Rovers, apparently, are much worse.

[Mark Hammond]

I can vouch for P5 Rover screens being tricky.  PA Cresta screen is the hardest I've fitted...

Will the car be ready soon Nick?  I for one will miss this thread once it's finished.

Mark

[Nick Moore]

Never fear Mark, this thread has some way to go. I updated the to-do list on the garage blackboard this afternoon:

• resleeve brake master cylinder, finish brakes,
  
• make the fibreglass section of the gearbox tunnel, finish the carpet and trim around the gear lever,
  
• modify and fit the headers (still in Melbourne), mate them up to the new stainless steel exhaust system sitting on the garage floor,
  
• fabricate the inlet manifold,
  
• modify the US-spec seatbelts so that they're Australian Design Rules-compliant, and
  
• fit a large radiator
  

So just a few things! My intention is to have it on the road later this year, and then no doubt there will be a few teething problems. I have a road trip in mind for it at Christmas...

[Nick Moore]

Jobs on the go, or next to do...

[Nick Moore]

I managed to jag a couple of days at home, both of which have been spent in the garage. Firstly I replaced a 0.75" clutch master cylinder with a 0.70" to reduce the pedal pressure. It's worked - the pedal's not too stiff, and take-up is a couple of inches off the floor. And amazingly, the system self-bled. I just jiggled the pedal for a couple of minutes, and gradually it got firmer as the air worked its way out. The shape of the Toyota slave cylinder may have something to do with it, who knows?

The big news, though, is that my Gareth Thomas header primaries are here and have been trial-fitted. There may have been a happy-dance when they arrived, as they took about two years to migrate from Wales to Western Australia to South Australia to me in Queensland. There are also rumours that they spent time in France!

The deal with Gareth is that I will get the secondaries made here, but they're much easier to fabricate than the primaries. The twists and turns necessary to fit six equal length primaries in that space are surprisingly complicated. As expected though, they need some tweaks.

• Firstly, the 2&5 secondary was touching the suspension turret. That was cured by bending the turret's lip forward slightly, giving a few millimetres clearance.
  
• Next, the same 2&5 secondary is hard up against the steering column.  I may be able to move the steering rack a few mm to the right to compensate, or move the engine slightly to the left. Failing that, a small dent in the pipe may be required.
  
• Lastly, the 2&5 points slightly towards the chassis rail's inner flange by about a quarter inch. Again, a BF hammer may be deployed to reshape the flange, and the secondary downpipe may need a small dent. Spitfire 1500s had a notch in their chassis rail to accommodate their downpipes, but I've also read that the notch weakens the chassis rails. If reshaping the lip doesn't work and I have to notch the chassis flange, I'll weld a strengthening rib or two to make up for the lost metal.
  

[booley]

Good stuff, Nick! I have been "lurking" here on your build thread for a very long time, eagerly awaiting any updates...
Must be your busy season down-under?
Are your motor mounts bolted to the front side or back side of the upright flange? Isn't that an easy way to shift the lump to the rear a tiny bit?
Imagine the space you'd have if you kept LHD ?!?

I remember having to "modify" that frame rail flange with a BFH when fitting a 6into1 header from JC Whitney, a looong time ago...

[Nick Moore]

Hey Booley,
Yes, it's our busy season at work. We'll stop work over summer when the rains start. Until then, I get home about every three months. It's not all bad though, as I have the Herald at work with me. I drove it this morning!

Lurk away! I've followed a lot of threads by restorers far better than I am, in the hope that some of their talent will be assimilated. Some days I think it's working, others not so much. For example, after I took the header photos on Wednesday, I got my largest adjustable spanner and bent the suspension turret's flange forwards. It'll need a touch-up where the enamel flaked, but that's no biggie. Finding a 1/4" in the GT6 is an achievement. However, when I stood back to admire my genius I realised that the spanner had squashed the right hand brake pipe! Fortunately I have a roll of kunifer pipe and a flaring tool, but still...

And yes, I could move the motor back, but the sump's steering rack recess is right above the rack, so I think it's where Triumph intended. Plus, clearances are tight at the gearbox end. The gap between the chassis rail's inner edge and the speedo angle drive is about 1/4", maybe less! In any case, there's no need now the turret's been spannered.

LHD? Yeah, that would make fitting the headers much easier, but while avoiding the steering column conundrum but would lead to an oil filter fiasco.

To be continued, next time...

[Nick Moore]

Now the Herald and I have returned from holiday, tinkering on the GT6 has resumed. Because the next long drive will be in the GT6, the mile-eater.

Firstly, the NOS-but-rusty tandem master cylinder is away getting resleeved in stainless steel. It turns out to have a stepped bore, with the rear piston being 1mm smaller than the front. The reconditioner says that they usually resleeve these as a single diameter, and make a new larger diameter piston for the rear circuit. That's OK by me - given that the rears are un-boosted, the rear brakes need all the help they can get.

I'm also getting two cunifer lines made up. One was made by me and the flares don't seal properly. Whether it was my fists of ham or my cheap (ish) flaring tool, I figure that the professionals can do a better job. The other line runs under the engine and was accidentally crushed when I was reshaping the right hand suspension turret to accommodate the headers. Ooops.

And now a question. I bought and fitted a GT6-style stainless steel heater return pipe, back when I was planning to run the car on carbs. It's not right for an injected motor as it angles out from the engine, and is only supported at the water pump. So, I can fit a PI pipe or a TR6 pipe. The PI pump appears to be supported by a tab bolting to the rear exhaust manifold / head stud, while the TR6 pipe's bracket appears to bolt to the engine to bellhousing bolts. I have a TR6 rear plate, so the TR6 pipe should bolt right up. Does that sound right?

Oh, and if anyone wants a GT6 stainless heater pipe, let me know. Free plus postage.

[Mark Hammond]

Welcome back!  I for one have really, really, really missed this thread!  I know that you've still been around but I can't wait to see the finished GT6!

Mark

[Tim Bancroft]

Nick,

What Mark said, welcome back green GT6!!!

Noticed that may have a Smiths mechanical temperature gauge fitted to the car, I have had issues with these in recent years, have changed to a similar one as manufactured and sold by Ractech, better made and hopefully more reliable!

http://www.demon-tweeks.co.uk/performance/gauges/racetech-water-temperature-gauge-mechanical

More than likely possible to find a stockist selling these cheaper than Demon Tweeks, although I think there prices have fallen in recent times.

I may have said this before, but I would love to see this car in the flesh, oh well. Good luck with the continued build.