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3 hours ago, radiomike7 said:

The weak point on the rear bogie is the third diff which has a drop gear for the leading axle pinion running on a steel shaft with no bearing.  Being at the top of the third diff it gets limited amounts of lubrication and can seize in seconds if one axle is stationary and one is turning, you would most likely get away with it for a brake test but not if one axle spins relative to the other if bogged.  I have spoken to my local LGV test station and they will come back with clarification as to what is acceptable. 

Thank you very much, I just don't want to take unnecessary risks. If there is a horrible noise during the test it would be very bad indeed.....

Iain

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Well it didn't go quite to plan. The test was aborted as the inter axle dif lock appeared to be stuck on. The dif lock indicator which shows pressure in the actuating line was off but during roller test the next axle was trying to drive when one wheel was moved. The test machine is automatic and stopped itself each time. All we could think to do was tried at the time to release it but we ran out of time and now I have to fix it and return next week for a full test at the full rate, £170.

Any ideas, could this have been normal?

Ill get the book out and have a read but there looks to be an access plate on the end of the dif lock. So thats where I will start. Suppose.

Iain

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Two possibilities, either the diff lock actuator is not working correctly or the gear I mentioned earlier has seized on the shaft and effectively locked the diff.

The easiest way to get it though the test if it is the diff will be to simply remove the inter axle propshaft, engage the third diff lock and run it up as a 6x2, if you run out of traction you can still engage the front axle.

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10 hours ago, radiomike7 said:

Two possibilities, either the diff lock actuator is not working correctly or the gear I mentioned earlier has seized on the shaft and effectively locked the diff.

The easiest way to get it though the test if it is the diff will be to simply remove the inter axle propshaft, engage the third diff lock and run it up as a 6x2, if you run out of traction you can still engage the front axle.

Thanks for your continued help!

I have until next Thursday (5th) so will look into it and fix if I can, luckily I still have rolling spares outside if needs be.

I did have a sticky actuator a few years back and freed it off etc but that's as far as I have been. Hopefully that's all that's wrong this time but I'll get the book out and give it a good going over and learn some more no doubt.

I think taking some oil from the axle drain for a look just in case.

S It was lovely drive though, 18-20deg and lovely sunshine, just like a summers day, that's part of the joy of having these things. I really enjoyed that part of it so not a complete (expensive) loss.

 

cheers

Iain

 

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Success, it was a stuck actuator same as before. It must be moisture and crud coming through the air system but it was actually around 10 years since I last cleaned it of crud, so not so bad. I have been making a habit of actuating the dif lock and front axle now and again and listing for the clunk, but I have missed out checking for the clunk lately. That's cost me an extra £179.

Ill put some pics up in a bit, cup of tea required.

Iain

Edited by Mk3iain

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Here are some pics of the actuating piston in the stuck position with a parts drawing of the dif assembly. After some cleaning with an abrasive pad and oil it started to loosen up and is now working as it should. Phew!

 

Axle dif.jpg

IMAG0001.JPG

IMAG0002.JPG

IMAG0007.JPG

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On 1 March 2019 at 1:31 AM, radiomike7 said:

Result, the other option would have been a pain.

Too right, it's a huge relief!

Should go a bit faster, maybe🙂

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Sadly failed it's test.

But not terribly;

1. Service brake failed due to lack of stopping power.

2. Headlights have European lenses.

3. a couple of bolts need tightening.

last two are a quick fix.

The service brakes are adjusted correctly, there are no leaks and the liners are good as new(last time I looked). The examiner recommended using abrasive on the front drums in case they were glazed. It should only take improvement of the front brakes to pass. I have not used the truck for a while and don't overwork the breaks when I drive.

Could it be lack of use?

Any suggestions!

All help appreciated 

Iain

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Does it have slack adjusters that you can move the clevice on the brake chamber rod to a different hole to increase length and leverage.

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This LGV mot is much more serious, and expensive than the car one. 

I have just had my Renault Maxter pre MOTed and it has thrown up a whole load of things I never expected to be a problem

Most are easy to fix , missing rear marker lights, spare wheel (which affects the side bars) , a missing exhaust bracket, an air leak from the drivers seat and the spray suppression mud guards are not widenough  

Others not so easy an air leak from the brake master cylinder and most problematical of all it has a left hand drive headlight.

I cannot find a right hand drive one. I have tried Ireland, New Zealand, Australia, India to no avail. I don’t know what to do next. 

My thoughts are re fabricating the front bumper so as to fit Military 24v Landrover lights. Should look ok. Or cutting the end off the bumpers and welding in the ends from something much younger probably a DAF with a steel bumper. 

Hey ho when I do sort out all this then at lest it will be done for good. 

David. 

Ps anybody got a 10 stud wheel and legal tyre  size not important they could sell me. 

CD243E94-E0F6-46AF-97AA-9BC7E9341C21.jpeg

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23 minutes ago, john1950 said:

Does it have slack adjusters that you can move the clevice on the brake chamber rod to a different hole to increase length and leverage.

No slack adjusters, the front uses a set of holes on a quadrant to take up wear adjustment. The front ones are on the second hole and have the correct amount of play and have 3 or 4 more holes to go to compensate for wear.

On driving home I took the opportunity to do some hard breaking and managed to lock up rear wheels once. It seemed to stop quite well, considering the weight and age.

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11 hours ago, david56 said:

This LGV mot is much more serious, and expensive than the car one. 

I have just had my Renault Maxter pre MOTed and it has thrown up a whole load of things I never expected to be a problem

Most are easy to fix , missing rear marker lights, spare wheel (which affects the side bars) , a missing exhaust bracket, an air leak from the drivers seat and the spray suppression mud guards are not widenough  

Others not so easy an air leak from the brake master cylinder and most problematical of all it has a left hand drive headlight.

I cannot find a right hand drive one. I have tried Ireland, New Zealand, Australia, India to no avail. I don’t know what to do next. 

My thoughts are re fabricating the front bumper so as to fit Military 24v Landrover lights. Should look ok. Or cutting the end off the bumpers and welding in the ends from something much younger probably a DAF with a steel bumper. 

Hey ho when I do sort out all this then at lest it will be done for good. 

David. 

Ps anybody got a 10 stud wheel and legal tyre  size not important they could sell me. 

CD243E94-E0F6-46AF-97AA-9BC7E9341C21.jpeg

That's just daft to use such special light in a military truck, and very frustrating for you. Just so happens the ATF I am visiting is a Renault dealer.

I have to say that the process of applying for the first test with VTG1 and dealing with DVSA has been fairly straight forward. They are helpful and do understand what these vehicles are.

The one problem I have found so far is that the system of applying makes you pay a test fee direct to DVSA and then you are left with the lane fee charge at the ATF. Unfortunately the ATF will also want to charge the test fee as this is how it is done on a day to day basis. Something they need to look at. I've had a very frustrating time with this but we are passed that now. I hope...

I was supprised when the examiner took out the emissions tester but he was more supprised at the result. Tested as cat B pre 2008,  (whatever that means) the first pass limit is 1.50, the Milly averaged .35 with zero drift. Not sure what is being measured exactly but the result was bloody good, not bad for an old AEC!

Iain

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Proves AEC engineers knew what they were doing in the engine build dept. You could lift the air pressure 5 to 10 psi. Its probably low after all of these years. Would a continental type beam changer be legal on the Maxter?

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5 minutes ago, john1950 said:

Proves AEC engineers knew what they were doing in the engine build dept. You could lift the air pressure 5 to 10 psi. Its probably low after all of these years. Would a continental type beam changer be legal on the Maxter?

The air pressure shows on all gauges to be in the correct range and the unloader valve seems to be operate correctly, but during test pressure was getting down to 80-90 psi. I tried to maintain it as high as possible but could not always do that.

Would it be worth taking the front drums off and de-gazing them with a bit of sandpaper or something?

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If there is a maker's name and part number on the headlights, it may be possible to cross reference them to other makes of military spec lorries and then find the correct headlights. Another thought, is there room to fit a standard  round sealed beam unit in place of the current headlamp? 

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John,

 

As others have said, check for glaze on linings.  As for air brake system pressure, this is crucial.  Make sure that the unloader valve is cutting out at, at least, the maximum pressure stated in the manual.  I have an EMER and can look it up if you need.the correct figure.  I think that it should be at least 100 psi.

The next point is to fit an air pressure gauge to read the pressure at the front air actuator cylinder.   It is possible that a relay valve is not applying absolutely full pressure to the front cylinders.  With the brake pedal fully depressed, you should get full reservoir pressure at the cylinders.

John 

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24 minutes ago, attleej said:

John,

 

As others have said, check for glaze on linings.  As for air brake system pressure, this is crucial.  Make sure that the unloader valve is cutting out at, at least, the maximum pressure stated in the manual.  I have an EMER and can look it up if you need.the correct figure.  I think that it should be at least 100 psi.

The next point is to fit an air pressure gauge to read the pressure at the front air actuator cylinder.   It is possible that a relay valve is not applying absolutely full pressure to the front cylinders.  With the brake pedal fully depressed, you should get full reservoir pressure at the cylinders.

John 

Thanks John

I've done the lights and general tightening and I am left with improving the brakes before next Friday. Plenty time to take the wheels and drums off and yes good idea to check the pressure at the actuators. The only thing in the front brake line is the dual foot valve so it should be simple...

Ive got a manual for the Mk3 cargo and it has the data for the unloader valve etc It does not though give any torque values for suspension parts such as axle/Spring bolts. It just says tighten. Any torque values for these and any other suppension parts would be helpful, if they exist.

 

Many thanks

Iain

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Iain, I was just about to post exactly what John A has suggested, it is the friction material that could be glazed rather than the cast iron drums.  You may strike lucky and find the AEC has pressure test points in the braking system which would make checking the pressure in the front system easy, some of the Scammells certainly had them.

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2 minutes ago, radiomike7 said:

Iain, I was just about to post exactly what John A has suggested, it is the friction material that could be glazed rather than the cast iron drums.  You may strike lucky and find the AEC has pressure test points in the braking system which would make checking the pressure in the front system easy, some of the Scammells certainly had them.

Thanks,

Its what the examiner suggested, as the service brake came out as a general fail he felt improving the front brakes should be enough.

looking at the test printout the measured vehicle weight is noted as 23500 kg. I take it the test machine is working this out itself, it's more that I had thought by 2500kg.

Iain

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Hopefully here are before and after shots of the front offside brake liners.

They did look a bit polished on the surface but after a bit of time with 60grit on an da sander (with dust extraction and mask) they look much better.

I do not have a trained eye and cannot be sure I've improved things. What do you  folk think?

 

image.jpeg

image.jpeg

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18 hours ago, Mk3iain said:

 

The one problem I have found so far is that the system of applying makes you pay a test fee direct to DVSA and then you are left with the lane fee charge at the ATF. Unfortunately the ATF will also want to charge the test fee as this is how it is done on a day to day basis. Something they need to look at. I've had a very frustrating time with this but we are passed that now. I hope...

Hi, I use a bus company ATF locally to me and I book tests directly with them and only pay once. Are you booking through DVSA?

 - MG

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1 hour ago, TooTallMike said:

Hi, I use a bus company ATF locally to me and I book tests directly with them and only pay once. Are you booking through DVSA?

 - MG

Mike

It was only for the application using VTG1 for first test.  DVSA insist on an upfront payment, give a reference number and send you to your nominated ATF to book. The ATF then take a lane fee in addition but many don't use the reference from DVSA and also take the test fee again. After that its all direct to the ATF, no need to include DVSA.

Very frustrating.

Iain

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37 minutes ago, Mk3iain said:

Mike

It was only for the application using VTG1 for first test.  DVSA insist on an upfront payment, give a reference number and send you to your nominated ATF to book. The ATF then take a lane fee in addition but many don't use the reference from DVSA and also take the test fee again. After that its all direct to the ATF, no need to include DVSA.

Very frustrating.

Iain

Frustrating indeed and I didn't know that was how it works for a 1st test. We have all that to look forward to in a few months with my mate's Berliet wrecker...

 - MG

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