Preparing for MOT

At the end of 2021, we had the big step of preparing for an MOT as documented in the many videos that we did on that subject with everything hanging on that one day with one person. Playlist Here

An MOT is very important however as many forget it is only valid really to say your vehicle passes the minimum requirements to be on the road at that second it is on a ramp or over the pit. It still falls upon the owner to maintain it to that standard and then there is us. We have a 1998 Dennis Dart that has not officially seen a public road since around 2013 when we believe it was withdrawn there are pictures from 2015 but the adverts inside show around the time of 2013 to 2015.

Then to add further to this the vehicle was scrapped although the DVLA will not admit to this, However in order to get a V5 we had to prove the vehicle was intact and the vehicle they had on file.

So with all that in mind we have done a lot of things to prepare for the MOT and other things to make it presentable for the public. We were under the impression at the time when we bought the vehicle that a member from TDTT was going to take it for a test as we returned with it so we could see what was wrong with the vehicle however they quickly backtracked on this when the doors wouldn’t close. This turned out to be a simple thing the pressure in the doors wasn’t building and it helps when the valve is open and all the buttons are connected to help build the pressure.

A few weeks pass and as it was being moved about inside the TDTT building and yard, A brake chamber decided that it no longer wanted to act as a brake chamber and hold Pressure when the service brake was used. This was replaced with much struggle and damage to a few other parts of the area which then also needed to replace.

Then to add to that the suspension decided that it no longer wanted to work. The level control is a rather basic system and works by two levers on the nearside (Pavement) of the vehicle these control the air flow to and from the airbags. The centre is level. if the arm goes down it releases air and the arm going up puts air in the bag. It’s a rather simple system however then the electrics starts to come into it. The only part of the suspension system that is electrical is the kneeling system. This is an extra valve that is controlled by an electric connection from the cab that releases the air out of both front bags to kneel the bus at the press of the other button it sends the system back to normal and fills the bags back to level, This is done with the aid of a sensor on the offisde (Road) which is a metal sensor and looks for a little flag on chassis when the sensor activates the bus believes it is kneeled and not at ride height. however when not stationary and with the handbrake off this is used to keep the bus at ride height by every time the sensor is triggered it fills the bags thus keeping the bus at a ride height set by the operator.

The sensor decided to go faulty so the bus was endlessly filling the airbags until this was replaced.

Another part that decided to break once parked at its new location was the handbrake This was replaced pretty quick and that air leak was fixed.

Further issues with the air system grew as it was being used, The airbags sit on a pedestal and mount to the body with a top plate, These top plates are a magnet for dirt and salt with that said can you see what is coming. Yes, you would be correct a rear top plate decided that holding air in the airbag was too much for it to manage and this needed to be replaced, This was replaced with an old friend.

A problem that haunted us from day one was the fact it did not start from the cab and there is no way at the MOT test center you can start it from the back try explaining that to the tester. With advice from someone at TDTT, we put an extra wire into a switch at the front which then could act as a starting switch. This worked for a while, Why do we say awhile well while fixing another issue which we will look at in a few moments, the switch stopped working and would just display the BUS STOP sign on the dash. This is far from ideal as we could no longer start the bus. We had a total of 3 to 4 days of problem-solving and trying to say outright why the ECU on the bus would not give the signal to crank, This was traced down to a fault inside the gearbox which we are unable to fix currently and the issue seems to go away once started. Once we had decided why it wasn’t working we asked our engineer who has only ever been on the channel once but knows his stuff. We asked how can we bypass these checks? Well with some creative wiring and a relay we have managed to bypass the check that the ECU does with the gearbox ECU and it cranks from the key. This was done to much upset of those on YouTube who in there fit in the comments sections said we were doing it wrong. At the end of the day, it starts from the key and as it is no longer a service bus there is only ever Mancbuses Staff that will be driving and starting the vehicle so we know the checks that we have to do.

As discribed above that issue was caused by this issue. The Dennis Darts have a repeater set of lights on the roof, This all worked apart from both indercators, We did hope this was a simple case of a wire being cut or a bulb broken we really hoped it was something really simple. How wrong could we of been? In the electric cabinet, there were two sets of the same relays and these were triggered by the indicators and it would give you the audible feedback that you was indicating. Shaun was tasked with getting these to work and what a challenge this was, As it was such a boring task of tracing and testing different yellow wires we never filmed this but a day was used with his head in the cabinet and making sparking and banging noises. In short, they had replaced part of the system when a section when faulty. although the relays were getting a signal to click they wasn’t getting 24v to the other contact that required it, soon as this was discovered and tested it was a case of findng a positive to feed the lights and the relays. Once sorted and rewired this caused the starting issue above. The electrics on this bus has been a challenge and we are hoping we have the tip of the iceberg now.

Apart from that preparing S114 KRN for the MOT is a simple task of making sure there is no sharp edges, All the lights work, The emissions look about right this has been a hit and miss but this has been sorted we hope and think. With everything sorted we have it booked in with Martins MOT Test Center a place we used when we had our beloved V176ESL. We hope it passes if not we atleast will find out what we need to look at to repair.

Mancbuses Team

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