BikerB · Jan 7, 2022

GSF 109 said:
Thought I would mount the PWDA valve, but as mine never had it from new, I didn’t have a bracket or the location for it on the chassis. After trolling through dozens of websites, I thought I would just make my own. There is also a load of info and discussion on which way round it goes, but it’s as simple as the 7/16” ports go to the front brakes and the 3/16”go to the rear. Mine is a five port version, so I will split two lines to the front and one to the rear. Just need to order up the unions…. View attachment 255926
View attachment 255927

I threw the bracket away for my PWDA valve when I cut up the chassis, there is always something!
I had pictures of where it went and had to make a new one like you did. As far as the pipes are concerned there is no right way from the parts book so I ran the front to a splitter on the front crossmember and blanked off the spare port in the PWDA with a plug. Mine originally had two separate lines from the PWDA to the front but it looked quite untidy, one pipe looks neater and needs less pipe.

Firebobby1 · Jan 8, 2022

Work looks lovely so far.
Is that a Triumph 2000 in the background

GSF 109 · Jan 8, 2022

Firebobby1 said:
Work looks lovely so far.
Is that a Triumph 2000 in the background

Thanks - yes, it’s a 1974 Triumph 2000 which I’ve had for around 12 years now. I’m a bit of a sucker for old British cars

GSF 109 · Jan 8, 2022

BruceB said:
I threw the bracket away for my PWDA valve when I cut up the chassis, there is always something!
I had pictures of where it went and had to make a new one like you did. As far as the pipes are concerned there is no right way from the parts book so I ran the front to a splitter on the front crossmember and blanked off the spare port in the PWDA with a plug. Mine originally had two separate lines from the PWDA to the front but it looked quite untidy, one pipe looks neater and needs less pipe.

The manuals are quite confusing, but I believe this is due to the master cylinder on a 109 and 88 having the front and rear ports reversed and it depends on which version they have referenced on the drawing. According to the drawings I’ve seen, the 109 v8 has twin front pipes due to the larger volume required, but the 1980 onwards 2.25 109 only has one. I will try the twin front pipes for now, but can always change it back if it fails miserably…

GSF 109 · Jan 9, 2022

Thought I would have a look at the gearbox tunnel diaphragm today as the other bulkhead bits should be heading to the paint shop tomorrow and I may as well do the lot at once.
It appeared to have been painted with rock hard black lumpy paint really badly! A sanding disc would have taken forever so I thought I would try some paint stripper and see how that went….

GSF 109 · Jan 9, 2022

I also tried a test area with the paint stripper on my replacement bonnet which has been treated with really dodgy paint. It has the feel and look of crocodile skin and is rock hard. My DA wouldn’t touch it and I didn’t want to damage the aluminium skin.

GSF 109 · Jan 9, 2022

After a few minutes, the paint softened and came straight off! This really is good stuff and will save me a lot of time

. I used an old metal scraper, but I will maybe try a plastic one next time so it doesn’t scratch the aluminium below.

GSF 109 · Jan 9, 2022

My 9 year old daughter did her bit too today. She rubbed down, primed and painted the bulkhead support brackets. I think she has done a great job…

GSF 109 · Jan 9, 2022

Once the diaphragm was stripped of the black paint, I applied it again and stripped the blue off underneath. I used the wire brush on my grinder and ground the surface rust off too. Think it was better than I was expecting! After getting down to bare metal, I knocked out some of the minor dings and straightened it out a bit.

GSF 109 · Jan 9, 2022

After some Kurust and zinc rich primer it looks almost ready to go to paint.

GSF 109 · Jan 9, 2022

Next I had a look at the drivers side front wing. Didn’t look too bad, but as I started dismantling it, the differential corrosion between the steel and aluminium is worse than I thought it would be.

GSF 109 · Jan 9, 2022

Nonetheless, I thought I would try sanding down the outer skin and it looks quite good. I think the master plan is to combine my 2 off side wings. My other one is sound where this one is not but the outer skin is bent. So, as they unbolt, I will take the out skin off and fit to the other.

GSF 109 · Jan 9, 2022

Found an interesting and aggravating issue with the fuel tank/sender unit. The outlet spigot from the fuel tank sender unit points directly to the breather pipe, so it will be extremely difficult if not impossible to fit a pipe onto it! I checked my old rusty tank and found the breather is actually installed in the wrong position. The joys of Britpart again….

Not too sure how I will solve it, but I’m sure there will be a way

BikerB · Jan 10, 2022

GSF 109 said:
The manuals are quite confusing, but I believe this is due to the master cylinder on a 109 and 88 having the front and rear ports reversed and it depends on which version they have referenced on the drawing. According to the drawings I’ve seen, the 109 v8 has twin front pipes due to the larger volume required, but the 1980 onwards 2.25 109 only has one. I will try the twin front pipes for now, but can always change it back if it fails miserably…

Do you know you had me thinking about this as my six pot generally follows the V8 for equipment and layout. I had to go back to the manuals and parts books to check that I hadn't made a boo boo.
The pre 1980 V8 has a single pipe to the front from the PWDA with a T piece on the crossmember. This is the way I have done mine for neatness as well.
I thought about the pipe volume issue and after a bit of thinking realised it makes no difference whether you use one or two pipes to the front cylinders, there is only one pipe down from the master to the PWDA anyway (although I think this is 1/4" or 5/16" rather than 3/16")
Mine had the twin pipes originally but it was a mess, the pre 1980 V8 had the same front brakes as my six pot but a single pipe system so it should be fine, panic over

GSF 109 · Jan 10, 2022

Sorry, wasn’t trying to confuse matters. I don’t think the manuals help at all either. I guess as long as it works and is safe, then it’s fine.
It’s interesting to note that the ports on the front part of the braking system are 7/16 including the master cylinder rather than the 3/16 of the rear part of the system. I believe this could be because 75% of the braking effort goes to the front and 25% to the rear. Also, on the 6cyl and v8 version they have larger brakes I believe?
The really confusing part is that the 7/16 unions have reducers to use 3/16 pipe! So, either that is incorrect i.e it should be 7/16 pipe with 7/16 unions which would allow a larger volume of fluid to reach the brake wheel cylinders? Anyway, not to worry, as long as it works properly

BikerB · Jan 11, 2022

Only one of the ports to the brakes is larger and it is still a 3/16" pipe, the union is just larger but the union is bored to 3/16"
The pipes going up to the master front and rear are larger dia pipes but everything I saw on mine on stripdown and from the parts catalogue says that all the brake lines from the PWDA to the front and rear brakes are all 3/16" despite the larger port sizes on the PDWA.
The brake system is not complicated, it just seems to have changed in details a lot over the years

GSF 109 · Jan 15, 2022

Got the bulkhead and panels back today from the painters and I must say I’m really happy with the way it looks now. Can’t wait to get the bulkhead bits back together and seeing it as one unit. Not to forget freeing up some space…

GSF 109 · Jan 15, 2022

Thought I would try and sort out the n/s wing tonight. The plan was to take both wings and separate the outer skin from both. I would fit the good original outer skin to the good inner skin I bought of a nice fella in Edinburgh years ago. Instead of trying to undo rusted bolts I thought cutting them off would be easier and considerably quicker!

GSF 109 · Jan 15, 2022

After cleaning off both mounting flanges, I gave them a scuff with 240 grit and some thinners to get them ready. I also thought I would apply some seam sealer, which may not be strictly necessary but it will help keep out moisture in the future

. Once it’s all gone off I will get on with prepping the rest of the wing for paint. I also noticed that the mounting plate for the mudshield had corroded badly. So, rather that make a new plate, I bonded on some new ally using aircraft bonding sealant. So it will never debond in the future and should strengthen the original somewhat. I also noticed a cut where I must have cut into the inner wing when I was cutting off the bolts holding on the washer pump

. Anyway I did the same with that to patch it on the inner. One it goes off, I will put a tiny bit of filler on the area you can see once when I am sorting out the rest of the dings.