45149 Restoration: 2004
 

With the locomotives ETH room more or less now complete (just the outstanding resistor frame to fit) attention is turned to the power unit. With our advisor, Mr Steve Madge, pointing us in the direction of what to do first, this view shows the first 4 heads being steam cleaned prior to dismantling and relapping of the valve seats. The coolant pipes were also steam cleaned before being overhauled and re-painted in our workshop van. Most of the coolant pipes have now been completed and are going to be removed from site for safe storage. We would like to thank the 'Brush Type 4 Fund' with their assistance in this part of the operation.

Once steam cleaned the cylinder heads were taken into the workshop at Toddington for dismantling and some lesons were learnt on how to dismantle the valves from the body using an adapter plate which forces the springs down enabling the tapered cotter sleeves to be removed. Once this is done the head is placed on the workshop bench for attention.

The two valves and the two retaining springs removed from the casting behind them, the label identifies the valve from the exhaust port, it is essential that each valve goes back into its respective port. Prior to the lapping of the seats, the valve bore is checked for size and ovality and if ok then we proceed with lapping the seats in

After an extended period of non activity on the loco due to not being able to work within the confines of the shed the loco was removed from on 18th April 2004 along with the roof panel for replacing on loco the following day. However, due to weather conditions this was postponed and work resumed inside the loco. Eventually on the 25th April 2004 the skies were clear and we were in business to place the roof back onto the loco.

Preparing for the removal of the pistons and liners on one bank was one of the next major tasks to be undertaken. We now have six overhauled cylinder heads and it is our intention is to pull six pistons and liners from A bank. The pushrod tubes and associated equipment have now all been removed in preparation for this. Many engine components have been cleaned up and are now stored prior to being refitted.

On removal we inspected the roller bearings of which each assembly has three in the big brass casting. Surface corrosion was found on them but not too bad. These assemblies have been dismantled overhauled and where necessary painted and now await re-assembly. The long rods attached to the rockers, which have also just started to be overhauled.

This view (right) shows one of the liners just having been removed from the power unit. The pistons were all removed first and then the liners were removed mainly so that we can inspect the condition of the liner seal, which you cannot see in this view but is like a large rubber 'o' ring. Although the engine had only 3000 hours it had stood idle for 17 years and we wanted to be sure that the said 'o' ring had not perished.

We also found once all the liners were removed that the water jacket (this is the large casting that the liners sit in) was full of debris and one of our helpers (benefactors) Mr Steve Benniston picked out a large piece of cardboard - god knows where that came from and the damage it could have caused. This made the whole exercise even more worth while.

Once the 6 liners had their bores cleaned we came back down to earth when we found one liner with a deep score and two liners with severe corrosion marks, in the new year we will have these machined to remove the scores. The bores were measured and we have sufficient material to remove the marks from the bores and, for the record, all of the liners measured perfectly round with no tapering in them and for the engineering minded people were all within .005 thou (imperial)

The pistons and liners were removed to our container and placed in piston stands, we only have enough stands to hold 6 pistons, which is another reason why we are only working on one engine bank at a time (our loco has 12 pistons). this view shows one of the removed pistons and shell bearing removed from the crank arm showing to the experts amongst you the damage to the while metal bearing surface. This is one of two damaged shell bearings which the group have got to replace. The pistons themselves and the rings are all in good condition and we will shortly be removing the rings from the pistons. This is the story of the power unit so far, the new year will see a lot more activity as we already have 9 overhauled piston heads and 12 overhauled fuel pumps waiting in the wings. Hopefully during the spring reassembly of one bank will begin and the dismantling of the other bank will take place.

So, what else have we been up to? Well number 1 cab is now on the home straight and hopefully during the April 2005 gala the cab will be open for inspection, the loco was placed in the bay platform at Todd.

Our newly installed second mans desk, the ETH controls of which the two switches were ceased solid and were thoroughly overhauled with new labels added to the panel all made by one of our members. The hand brake assembly on the left hand side of the secondmans side was removed and overhauled with a new handle. Originally the hand brake was powder coated but this just all fell off so we decided to emanel it and replace the large steel washer with a non corrosive alternative in brass. Also a new label was made with the hand brake on/off instructions as these were no longer available we replicated it in aluminium.