vario 614 warning light issue

[surfer4life]

Hope one of you folks can help with this.

i have a mercedes vario 614 (98 r reg), the one with the air handbrake but normal hydraulic brakes, i have a warning light that is intermittent and i can't work out what is for as the vario manual online seems to be more geared towards the newer vehicles. this is the light that is causing me trouble;



when i start the vehicle the normal air chamber light comes on like it should when there is not enough pressure in the air handbrake system and the light indicated above, the chamber light goes off first then the other light goes out with an audible click from under the passenger side dash, thats how it has been for over 3 years and i always thought the other warning lamp was something to do with the air handbrake.

the other day i was driving along and that warning light started to be intermittent, its very weird, sometimes it will come on when i press the brakes, sometimes it will go off when i release the handbrake, i can't replicate what sets it off, i have always had an audible click (like a relay click) when i press the brake pedal coming from the passenger side dash if this has anything to do with it?

Any ideas? its driving me crazy!

 

[Anton2k3]

Not an air leak which is causing low pressure this light on?


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[surfer4life]

possibly, but would that light come on for a low pressure air in the air system? The air chamber light, which i know for sure is to do with the air pressure does not come on, on panel number 2 on the pic.

 

[andylod]

Had a similar problem ...... the click you can hear is just the relay that operates the brake lights so no worries there...... I think you'll find your problem is the brake pad wear level sensors. Its either the pads are low, or that one of the wires coming from the pads has chaffed against the calliper metalwork and is shorting to earth causing the light to flicker. Is it worse in the wet ???
Hope this helps

Andy

 

[surfer4life]

great andy, i'll take a look, i was hoping it would be something as simple as pads.

the thing is when i look for that indicator lamp on the vario manual online, it says something along the lines of "do not operate your vehicle if this light comes on as there is not enough pressure in the air system" yet contradicts itself by saying that light is for brake pad wear and brake fluid level and if there was not enough air in the system then the warning light on the panel 2 of the brake chamber would come on surely?

once this is sorted i have quite a few other issues i will need help on, its great to see so many vario/t2 owners on one forum

 

[Anton2k3]

Hopefully Andy is bang on the money. Incidentally, on ours when the air tank is empty and has to recharge (after standing for a while), the air brake chamber light goes out some time before the brake warning light will. So, I think its kind of two stage, one for hardly any air, and one for your running low on air!

What are the other issues??

 

[surfer4life]

I hope so Anton

Other issues are there is an air leak in my power steering system, I think on the pre pump side, as when cold, it is sucking air in somewhere and causing the fluid to bubble up and flow out of the reservoir, if it was on the pressurised side it would be splurging out of the said leak, so must be on the vacuum side.

I also have an issue of the drivers side wheel heating up on certain parts of a journey, it always seems to happen on a certain stretch of road in north Wales, you can smell burning rubber so I have to pull over and let it cool down before carrying on, one time the tyre was smoking it was that hot. 3 things I can think of it being, 1. Calliper is seizing 2. Issue with the hub 3. Issue with the handbrake spring chamber.

I had the van in at a Hgv place near me last year to get the issues sorted and a service, £1400 later they didn't sort a thing, they just changed the power steering fluid, which I told them does not solve the problem, and regreased the hub and checked the brakes over. Went on holiday the week after and my wheel nearly caught fire again, weirdly on the same stretch of road as the last time

 

[ianc]

I presume you're talking about the rear wheel heating up?
Is the heat in the tyre or the rim/hub?

I'm not sure if the 614 is the same rear axel/brake setup as the 814DA but they do suffer from brake disk binding when crap gets into the mechanism. The ESB (Who run a load of 814DAs) chief mechanic said it was the single biggest problem with them and I should check this when buying.

I also would say that the brake is the only way to generate that level of heat and for there to be little trace of the source. If the hub was generating that much heat it would have stopped being a hub at this stage!

 

[surfer4life]

thanks ian,

i read somewhere that the hubs are also an issue and one mention of the axle actually catching fire, mercedes knew about this issue and then changed the hubs, don't know if this affected the 614 as it was mentioned on an 814. When i checked the first time it happened, i did burn my finger on the disk as the spit on the end of it vapourised very quickly. so the disk is getting very hot, but cant say for sure wether or not the caliper or hub caused it, this is then transferring heat to the wheel, which in turn nearly set the tyres on fire!

i am thinking more along the lines of rear caliper as you mention, but could a lazy compressor or faulty handbrake spring chamber cause it? maybe the handbrake isnt disengaging properly???? causing friction on the rear wheel assembly.

 

[andylod]

Surfer.

How long has this burning/heat problem been an issue .... can you see a noticeable wear difference on brake pads left to right on the rear ? Brake pads smell, although different to rubber .... are you sure the smoke was from the tyre as brake pads will also smoke.
My money would be on the calliper.

I would try to pressurise your steering system to see if you can find a leak .... maybe seal the lid with a piece of plastic bag under it, run the engine untill you feel a little warmth in the power steering return pipe under the reservoir. Then turn engine off and check for leaks on all pipework, connections and components. Dont forget to remove the plastic bag
It may also pay to try starting the engine and carefully removing the cap to see how the fluid is returning into the reservoir, it should be coming up from below or under the surface of the oil, if its coming in above the surface then it will make the oil foam (old volvo problem).

Andy

 

[Anton2k3]

I believe the hub re-design was due to the sensitivity of the old hub when changing the brake discs. If they were not done correctly, it would always result in a leaking hub seal. The new hubs eliminate this problem, but at great cost. You can't actually buy the seals from MB anymore, but instead have to buy a whole new hub assemble.

The symptoms sound like a dodgy caliper, or incorrectly adjusted after changing the pads. I changed the pads on mine recently and noticed a smell from the passenger side rear brakes. It seems to have fixed itself, but assume there was slight binding for a while.

 

[surfer4life]

thanks for the excellent replies guys.

firstly i hope it is the caliper, that would be easiest to do, i've been to the outer hebredies and back from south west wales and didnt really notice it, there was a slight burning smell on that trip on the very hilly parts in wales but i thought nothing of it, it was the year after i went to north wales and there is a certain stretch of road where there is a very long incline next to a valley and it has done it twice here a couple of months apart in exactly the same place yet it was fine on the way home. This is what made me think it could possibly be the hub as there is a lot of weight on the rear for a long period on that hill. also it certainly looked like the tyre was smoking and smelt of burning rubber, but maybe i was just in a panic that my van was about to go on fire and didnt check properly that it was the pads. The garage i had the work done at regreased the hub and it looks like they used liquid seal to seal it back up again :-( Based on your advice guys i am going to get a new caliper and new discs pads for the rear and hope it cures it.

The power steering is bubbling from the bottom so it is suck air in somewhere on the suction side. Thats a great idea to pressurise the inlet side, so simple lol, although i can't think of anything to use to create the pressure, i was thinking of taking hose off the reservior and somhow pressurising that to test for leaks with maybe a foot pump or something, then refill the system to get rid of the air i just put in. any better ideas?

 

[andylod]

The idea of sealing the cap will pressurise the system as soon as the oil warms up slightly (expansion) . Leave it sealed and check for leaks once you turn the engine off ( whole system with be full of oil and under slight pressure so should show leak )

The hubs and bearings run in oil from the diff. no grease is involved ....... Maybe check diff oil level just in case
The sealant you can see will be on the half shaft end plate. This is normal and stops the oil leaking out of the axle.

 

[surfer4life]

that makes sense about the power steering thanks.

i had the diff oil done at the time of the service last year, so i was getting confused with oiling and greasing, sorry. And yes the sealant is on the end plate.

so this diff seal that has been mentioned, is that going to be a problem when i change the discs? My truck does have over 250000 miles so i imagine they've been changed a couple of times, and would have been done properly aswell as it was maintained by mercedes all its life before i bought it 3 years ago (it was owned by nhs before me)

 

[andylod]

mmmmmmm possibly yes and no

have a read of this thread it may help http://forums.mercedesclub.org.uk/showthread.php?t=31482

Andy