Many thanks to Neil G, Jack Norie and Brian Watkinson for the great thread under 'Subframes' which detail the high pressure water filler system used on Mortlake buses at Mortlake garage.

As one of the very few Mortlake buses to suvive, i deceided to see if RM1403 still had the high pressure system and perhaps those in the know can advise if the pictures on http://www.facebook.com/media/set/?o.110663152296481 is the high pressure system. The pictures were taken on Friday 17th December 2010.

I have had to post them on facebook as the ROOF site does not allow pictures and the Alans site is locked to many people but if you cant access them then become a friend of 'A Route 2 Hire' and you can see them.

David

My bus number (if any): RM1403

I have set up a link on the following site as I understand that many cant access the facebook photographs. Follow the link below http://www.flickr.com/photos/57248659@N05/5276880114/
email me if you cant access these as well.

My bus number (if any): RM1403

Hi David

RM 1403 certainly does have the special Mortlake system. The device to the left of the header tank is the key to this though it was never red painted. Silver sprayed perhaps but I`m fairly sure they were actually brass.

The idea was that from a a mains water (pressurised) supply pipe that ran across the roof girders, a long hose hung down close to the bus wash to facilitate the topping up of the water system on the run in.

Forgive me if I`m stating the obvious but there are probably people who will read this and not understand the efficiently devised proceedure for `putting a bus to bed` when it `ran in` at the end of its working day.

Standard through all LT garages, a `fuel island` was where a bus arrived to have several things done simultaneously. Two `General Hands` would be inside the bus, one on each deck and both with a length of `hoover hose` which would then be fed through the rearmost opening window on the offside of each deck. This would then align with, and be connected to, the main industrial hoover so that each deck floor could be cleared of litter. Whilst this was happening another General Hand would place the fuel gun in the tank so that diesel was being dispensed until the automatic cut out activated when full and whilst this was happening the same man would then check and top up the oil and water. Another guy would be doing other bits including emptying the platform `used ticket` boxes and the `pre-washing` of the back end (or at least they did at Mortlake though you wouldn`t have thought it at other garages judging by the appearance of their buses). All these various tasks took roughly the same time and thus finished at the same time so that a General Hand Driver then took the bus on through the wash and parked it - having walked back from the one he had just done previously. Whilst he was going through the wash another General Hand Driver would have fetched the next bus to the fuel island thus keeping buses clear of spilling out into the street if the run in was that intense. And this efficient, carefully timed and devised proceedure was replicated every night in every garage.

But back to that hose which was part of the above process at Mortlake. It had a sprung attachment to connect with that device. The water was already `in the hose` so it needed nothing more than to be connected in an `air tight` way and left until the system had been filled under pressure at which point the surplus came spurting out of the overflow on the header tank giving, in theory, a system full of water and not air. But your overflow has a hose attached - where does it go to? It`s not part of the Mortlake system.

At all other garages the way of topping up the water was by hose or can through the header tank which obviously meant undoing the cap thus breaking the air tight idea. With cold heaters the first thing to do would be to top up the water. But often it would only take a minimal amount of water before it came bubbling back out of the tank and you would just know that it wasn`t full of water but probably full of air. So the next approach would be to get some revs up whilst filling. Ideally and safely this would involve someone in the cab - often the driver whilst the conductor tried to fill the tank. There is another way but I`m not going there as the scope for someone getting it wrong is too great and the consequences unthinkable. Those who worked with RM`s will know what I`m on about.

So at Mortlake we had a much better chance of efficient heaters - though the termostat could fail at any time negating the brilliance of the special system. It was that simple and it`s not beyond possibility that you could re-invent and use it if you`ve got a hose with the required attachment that`s connected to a supply.

My bus number (if any): RMs 238, 471 & 2213

Thanks Neil for a explanation of the high pressure system. Thanks to Chris for uploading the photos as well.

What you will notice in the photos is that the filler is not red but the same colour as the drivers cab side, It is the 'Benskins Brewery' maroon paint work which was painted by LT at Aldenham when the roof was taken off and put on RM254. Must sak Geoff Rixon when I see him if I can have my roof back.The bus was sold to Benskins in March 1984 and appeared in May 1984 in Benskins Brewery livery.

If the filler cap is brass then I shall attempt to take the paint off and return to a brass finish. It is good of Neil to answer this question in depth. I wonder how many other buses suvive with this system still in place.

In answer to the overfill filler pipe, if Chris can up load the larger picture, you will see the pipe comes out of the top of the thermostat and just hangs out to the bottom of the engine, attached with a cable tie to the chassis member.

Is there any other bits and pieces Neil and others can add about RM1403 and other Mortlake buses.

David

My bus number (if any): RM1403

Talking of header tanks can someone tell me why the majority have a sloping front while there are others that are square. I have a spare engine fitted with a square tank.

Didn't the sloping front ones have a black filler cap where the round blanking plate is - the one where AEC badges can be screwed to.

I guess that the square ones are a newer version.

So was the original version not presurised ?

My bus number (if any): RM1368

The engine cooling water system on the RM as opposed to the RT was always pressurised Mike and the header tank has a pressurised cap. The problem was filling up through the header tank and not directly into the radiator created airlocks in the heating system. To remove these filling was often done with the engine running or revving to try and get the water to circulate. This created a noise problem which the high pressure filling system also sought to alleviate.

My bus number (if any): RTL 960 and RMC 1458

I need to change the water / antifreeze mixture in the header / rediator / heating system.

Does anyone have any advise how this should be done safely and could I make use if the high pressure system installed on RM1403. The heating system in her is very hot even upstairs so by replacing the fluids it would be good to make airtight again.

My bus number (if any): RM1403

David

The only way you will be able to take advantage of the special system fitted to RM 1403 is by having a direct connection from a mains water supply under pressure into the device by the header tank. Look at the bore of that device. It`s tiny. And through it water needs to be forced under pressure - like fuel through an injector pipe. There`s no other way. You cannot stick a conventional hose over it and hope for the best. That`s why it was so special to Mortlake and when the garage closed the buses which were fitted with the system got scattered all over the fleet into garages that couldn`t use it. We had several ex Mortlake buses at Stamford Brook and it was really infuriating to know that such a clever system was in the bus but negated by an infrastructure deficiency in the garage. I wouldn`t mind betting that 99% of Stamford Brook drivers who topped up the header tank of an ex-Mortlake bus hadn`t got the slightest idea that this everyday act was totally at odds with the bit of metal poking up just inches away.

So unless anyone can advise you differently I`m going to guess that you`re stuck with the same proceedure that everyone else has to follow in letting the water out from the drain under the rad and filling up through the header tank. But why would you want to do this if you`re lucky enough to have great heaters? You must have properly circulating water if this is the case - better than many buses were in service. So long as it`s got adequate anti-freeze in it (which I hope has been the case recently!) and is ideally parked with the rad facing away from the coldest winds, I`d be inclined to leave it alone unless there`s a very good reason not to.
What do other readers of this think?