Superaquarama Posted March 3, 2015 Report Share Posted March 3, 2015 (edited) Am I being dim here ? I mean, the plenum is the box area below the scuttle vent, right ? So why has our car got no drain holes ? We're at the paint stage now (at last !) and I need to do the draining mod before it all goes together, but where should the drain holes be ? Corners. presumably, but front or rear, as it all seems pretty flat ? Thanks, Anthony Edited March 3, 2015 by Superaquarama Quote Link to post Share on other sites
bob-menhennett Posted March 3, 2015 Report Share Posted March 3, 2015 (edited) A Google image search on " Triumph TR4 plenum " throws up a very rusty plenum section, showing the stub drain pipe in the corner.As viewed from underneath. I assume that in a former life, your car was patched over, i.e. no drainage, when the metal stubs/ bottom of the plenum rusted through. Once rectified, carry out the modification of running the rubber drain hose down into the sill section and immediately out again, on the vertical sill section( inboard ) onto the road. An alternative route is via the metal baffle plate 750150 /750151 / splash panel. having drilled a hole through them.A picture is in the Moss catalogue 2014 Front Inner body panels and fittings pages 116 or 118. The original drain pipe route finished sandwiched between the outer wing and inner body tub , simply dripping water onto the sill.Rusty sills followed shortly thereafter as part of the design fault. Pictures are in Roger Williams book " How to restore Triumph TR4 & TR4A " ( ISBN number 1-903706-04-1 ) chapter 4, page 50.Your local library should be able to help you out if you don't have a copy. Suitable rubber grommets for the newly drilled holes recommended after you've had the paint job. Bob Edited March 3, 2015 by bob-menhennett Quote Link to post Share on other sites
graeme Posted March 3, 2015 Report Share Posted March 3, 2015 (edited) Corners. presumably, but front or rear, as it all seems pretty flat ? Anthony Anthony, Your description of the plenum doesn't sound right, maybe plated as Bob mentions above. Here is a picture behind the dash area of the LH side of a LHD car. The drain is marked with a circle on the left of the picture. There should be a corresponding drain on the RH side also. Cheers Graeme Edited March 3, 2015 by graeme Quote Link to post Share on other sites
4Mal Posted March 3, 2015 Report Share Posted March 3, 2015 If you pm me your email, I'm sure I have a photo of the mod made to my 4 Quote Link to post Share on other sites
stuart Posted March 3, 2015 Report Share Posted March 3, 2015 You will possibly find that they were deleted because this had happened. I always run the drain out and through the bottom of the splash panel and add an extra drain on 4/4a/5 for the drip rails like this Stuart. Quote Link to post Share on other sites
4Mal Posted March 3, 2015 Report Share Posted March 3, 2015 Simiar to mine Stuart Quote Link to post Share on other sites
mike3md Posted March 3, 2015 Report Share Posted March 3, 2015 As a point of interest, is it possible to fit the extended drain tubes without taking the wings off? Mike Quote Link to post Share on other sites
Tom Boyd Posted March 3, 2015 Report Share Posted March 3, 2015 Yes it is possible, it's a fiddle but can be done Quote Link to post Share on other sites
Superaquarama Posted March 3, 2015 Author Report Share Posted March 3, 2015 (edited) Mmm, this is a bit bizarre - we don't seem to have a plenum chamber per the photos at all, let alone drains ! The car's a 4A which came in from California and had very little rust, although we did replace the floors as per usual and also the panel below the battery; that was about it. Even if it had a 'heater delete' option originally, like some warm climate American cars, surely it would have still had the plenum, and anyway it has a heater and the controls, although the car was in bits when bought so I never saw how it went together. The box below the scuttle vent was and is rock-solid, incidentally. In any event, it looks as though I'll have to get a plenum chamber if they're still available, or fabricate one if not. Many thanks to you all for the comprehensive replies and particularly for the useful photos. Edited March 4, 2015 by Superaquarama Quote Link to post Share on other sites
RogerH Posted March 4, 2015 Report Share Posted March 4, 2015 (edited) Most odd indeed. Can you post a pic of what you have (or haven't). I would have thought that the plenum would have added to the structural strength of the dash area considerably. Roger Edited March 4, 2015 by RogerH Quote Link to post Share on other sites
Superaquarama Posted March 4, 2015 Author Report Share Posted March 4, 2015 Doh, doh and thrice doh ! I was looking in entirely the wrong place for these drains, I thought they'd be exiting somewhere below the scuttle vent, not out at the sides of the scuttle ! So I've found the blighters now and everything is after all as it should be, and pleased to say that they're rock solid so I can get on with the modded drains. So humble apologies to all for setting this false hare running, but thanks again for all the help in focussing on it, without which I'd still be stuck. Quote Link to post Share on other sites
littlejim Posted March 5, 2015 Report Share Posted March 5, 2015 At thetime I was doing mine some forum sage advised pointing the end of the tube to the rear to avoid blowback, so I pointed the end of mine back. Quote Link to post Share on other sites
swood1 Posted May 12, 2015 Report Share Posted May 12, 2015 Hi all, I did some searching on my newly purchased TR4a last night. It was rebuilt around ten years ago. I have found the drain outlet from the plenum for which it has a pipe on it but I cannot find the end of it. I have the fibreglass panels in the wheel arches but doesnt look like there are any hidden outlets behind them. I am thinking next step will be for me to remove a front wing so I can confirm where the pipe goes unless someone else can advise of possible exit points. Regards Steve Quote Link to post Share on other sites
RogerH Posted May 12, 2015 Report Share Posted May 12, 2015 Hi Steve, if you remove the wheel arch liner and the infill panel between body and wing you should be able to see what is going on. If you have a short stubby drain allowing water to flow onto the sill it will eventually rot the sill away. You need a longer pipe venting the water away from the sill. Can be fitted without wing removal (I think) Roger Quote Link to post Share on other sites
swood1 Posted May 12, 2015 Report Share Posted May 12, 2015 Thanks Roger for response. This weekend I shall have a look, would be great if I can fit without removing wing if required. Steve Quote Link to post Share on other sites
Tom Boyd Posted May 13, 2015 Report Share Posted May 13, 2015 Yes it can be done with the wing in situ, bit of a fiddle but possible Tom Quote Link to post Share on other sites
harrytr5 Posted May 14, 2015 Report Share Posted May 14, 2015 Revington TR does a neat drainage kit and I have fitted these to my TR'S. i drill through the top of the sills and exit out of the side of the floor pans.If you would like a photo PM me and I will email it back if that helps. Regards Harry Quote Link to post Share on other sites
Tom Boyd Posted May 14, 2015 Report Share Posted May 14, 2015 This is an example.. Quote Link to post Share on other sites
aleda Posted May 20, 2015 Report Share Posted May 20, 2015 Hi there This is what I had done last year when sill had to be replaced. The drain tube goes through the sill with about half an inch poking out the bottom to check it doesn't get blocked. Christine Quote Link to post Share on other sites
RogerH Posted May 21, 2015 Report Share Posted May 21, 2015 Hi Christine, does the lower end of the pipe come out on the vertical face of the lower inner section of the sill. If it does then it is very functional. If it goes straight down then the bottom of the wing may have an interesting time when fitted. Roger Quote Link to post Share on other sites
aleda Posted May 23, 2015 Report Share Posted May 23, 2015 Hi Roger, the hose (which is one continuous smooth bore hose) goes vertically down from the joint with the short upper rubber hose. It enters the sill cavity through the upper horizontal surface and turns 90 degrees (a gentle bend) and exits through the inner sill cavity wall which is a vertical steel panel. And the pipe extends about 20mm which ensures it cannot retract back into the sill. The whole procedure is simple and cheap and merely requires that the 2 holes (top and inside edge) are aligned so that the hose can be pushed through. The hose is a snug fit in the holes so will not move or become dislodged. Additionally my mechanic advises me that the passage of air beneath the moving car will help to suck anything within the hose via the siphon principle. All parts bought from B&Q for under £10. I'm merely listing all this out for the benefit of others, not you Roger. BTW Betty in hospital awaiting exploratory op to see what's causing her 'clunk, discounted UJ's as service history shows done. One wonders how many miles uj 's last? Christine Quote Link to post Share on other sites
RogerH Posted May 23, 2015 Report Share Posted May 23, 2015 Hi Christine, UJ's last anything from the odd 1000 miles to 10's of 1000's. Roger Quote Link to post Share on other sites
Vic787 Posted June 14, 2015 Report Share Posted June 14, 2015 Excellent Topic re Plenum drains, made me think, I know when I rebuilt the car I fitted the drains but due to this I will check mine now and look at the drain exits. Fantastic Forum 4 We tr4rs Quote Link to post Share on other sites
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