Hi everyone,
I need some help with my compressor… This is the third compressor I’ve had on the vehicle, two have been on and off in the last 12 months. They just seem to leak oil.
My second one had some contamination inbeteen the reed valve which caused the pressure to build and blow the head gasket (not covered by warranty). Then the current one is just pi**ing oil out from what looks to be a blanking bung.
I’ve had a new air filter on and still can’t seem to get to the bottom of the issue. Really hope someone can help me as it’s getting me down
Thanks in advance !!
Charles.
I don’t think the Newbie forum is the place for this mate! 
Try the owner/fleet forum…
Oh, sorry about that mate.
Will post something similar in there…
Cheers
Hi everyone,
I’m having some serious issues with my braking system. When I say braking system I mean my air brake compressor. I’m onto my third one in the last 12 months!!
The second one I had was still under warranty so was sent off to Knorr-Bremse for a bench test - they rejected the claim as it had some contamination between the reed valve causing pressure to build and blowing the head gasket
My current compressor is made by the same company and now oil seems to be leaking from a blanking bung underneath where the compressor sits on a plate, next to the engine.
Surely there must be some sort of underlying problem or issue as to why things keep going wrong with the compressors. In/out feeds have been checked for damage and the filter is new so I just can’t seem to get to the bottom of this.
Hope someone can help…
Thanks in advance
Is the engine breathing heavy? Does it use much oil?
Age, mileage, make and model of vehicle, long distance or multidrop city deliveries?
It’s a land train based on a Land Rover td5. Only got 16K miles on the clock. It’s runs more or less for 6 hours a day at speeds no faster than 5/10mph.
Doesn’t use excessive amounts of oil either.
Wearing my deerstalker hat, peering through my magnifying glass and having had a word with Watson, I think that now I understand correctly this is a narrow gauge railway locomotive we are talking about with the Land Rover TD5 engine. It trundles up and down a track at 5mph approx at low revs and spends many hours idling. During the course of its life it has covered 16,000 miles but you haven’t mentioned how many years it has taken to accumulate that total. It presumably pulls several air braked coaches and the compressor has to spend a lot of its time pumping to maintain pressure because of leaks in the pipelines, it may even be pumping almost constantly. I am not particularly surprised that you have compressor problems.
I will guess that the compressor is belt driven from the engine since you mention that it is mounted on a plate. I will take a leap in the dark and guess that the compressor is oil fed from the main engine. I know next to nothing about the TD5 engine except its CC and what I have been able to read, which does not say whether it is direct injection or indirect. It does appear to be fitted with an EGR system. So if all these statements are true then it is quite probable that the EGR system is contaminating the engine oil with carbon, if the engine is indirect injection then the condition of the engine oil deteriorates far more rapidly than otherwise. Since the engine operating conditions are presumably as described then the compressor is being fed with contaminated oil and having to work very hard as well. I would not be surprised upon removing the engine rocker cover to find a lot of sludge and carbon present. If all this is true your problem lies within the engine.
It the compressor is not oil fed by the engine then you had better do something about that oil leak before it has all gone. In either case if the pipework downstream of the compressor is partially blocked with carbon (you only mention damage) or the compressor governing/unloader valve is faulty then this is a significant cause of your problems. What drains out of the air reservoirs will be interesting.
Thanks for your reply, may I call you Sherlock…?
It’s a road based Land Train so it doesn’t run on tracks, it’s basically a converted Land Rover, very similar to the one in this link: letsgoout-bournemouthandpool … and-train/
It’s taken around 8 years to get to 16k miles, however I’ve been running the business for the last three years in which I’ve racked up around 1500hrs of drive time. There are no leaks in any of the brake lines, we carry out daily infection checks plus have a mechanic who comes out every 6 weeks to carry out a full I pectin which meets the councils health and safety requirements.
You’re good…the compressor is belt driver and yes, it’s also oil fed from the engine. How does it affect the engine if it’s direct or indirect injected?? Also, would replacing the EGR valve solve my problems or is there a more complex solution.
Thanks again for your help, finally feel like I’m getting somewhere. School holidays are only around the corner and we all know what that means… WORK !!!
Cheers !!
What’s the best way to clear carbon from pipes? Would an air line work or would it need fully replacing? Mainly water with a slight oily texture but this is normal apparently.
it could be an oil contamination problem but I would also consider the potential for the confined engine compartment in a Land Rover to not allow sufficient cooling particularly as I’d suspect this type of vehicle spends a lot of time idling.
Either way I would consider installing a 12v electric powered compressor somewhere else entirely away from the engine heat.
Evil8Beezle:
I don’t think the Newbie forum is the place for this mate!
Try the owner/fleet forum…
That’s a great idea 
I’ve moved and merged the posts here so that all the answers end up in the same topic.
The compressor has the same needs as an engine in order to perform reliably. Clean oil, clean air and adequate cooling, the only thing it doesn’t need is fuel. Similarly to an engine it doesn’t take well to being overloaded, which is why the manufacturers specify a duty cycle. In brief this means it is not designed to be working flat out all the time. So:
Clean air. The cooler the better - within reason. It will either have it own air filter or draw air from the main engine’s inlet trunking. Adequate cooling. It will either be water cooled from the main engine’s circuit, or air cooled in which case the casting will be finned like a motorbike engine.Clean oil. It will have its own sump or will be pressure fed with filtered oil from the main engine.
Particularly if, but not only if the main engine spends a lot of time idling, runs at fairly low revs and/or load a significant amount of the time it produces more combustion by products, especially in the case of an indirect injection diesel. Much of this is in the form of soot, this is made considerably worse if the engine has an EGR (exhaust gas recirculation) system. The soot in the exhaust gets fed back into the inlet manifold. At the same time the main engine will often feed its oil vapour rich crankcase gases (also contaminated with soot) to the same place. If the engine is idling a lot of the time and the compressor inlet air is taken from the main engine inlet trunking, even though this is upsteam of the contamination, then it receives a diet of comparatively unclean air. In addition if the engine compartment is poorly ventilated and consequently hot there is likely to be a fume laden atmosphere.
The air being fed to the compressor now gets pumped through to the reservoirs containing a small quantity of oil mist. As the compressor works it raises the heat of this air significantly converting some of the oil and soot into larger pieces of more solid carbon.This tends to stick to the walls of the pipework downstream of the compressor, gradually over time narrowing the bore of the pipes. One of these pipes is likely to be flexible and the hot carbon not only sticks to it but causes it to swell up internally. Some of this carbon and oil then reaches the filter in the unloader valve ( which regulates whether the compressor pumps or not) and starts to restrict it. The compressor now has to work much harder and longer to build up air in the reservoirs this making it run hotter and create more of its own carbon. If the air consumption demand is high ( likely to be in this case) the compressor will be very near to or beyond its duty cycle limits.
What can you do about this? There are some really nasty chemicals available to disolve carbon although Coca Cola does work eventually. You will have to remove the pipes and submerge them for probably at least a day to do this. You are probably better off just replacing the first length of steel pipe downstream of the compressor. Renew any flexible pipe as a matter of course. Carbon will build up particularly in any elbows or connectors. Without knowing how your compressor is controlled it is difficult to say specifically what to do, but your mechanic should know. Upstream of the compressor I would suggest that as said before, you check under the rocker cover to see if there is much gunge, you may even be able to tell by looking at the oil filler cap on the rocker cover. Also check for carbon build up in the EGR valve and manifold - again your mechanic ought to know what to do. He should also know to check the main engine PCV valve (crankcase ventilation valve) if there is one. Thereafter change the engine oil more regularly. If you should find a lot of carbon, sludge and solidified oil under the rocker cover, and I really hope you don’t, then speak to an engine reconditioner because you have a lot more than compressors to worry about.
Or as suggested bin the thing and go electric.
The TD5 is not indirect injection. At least one website shows a TD5 engine with the rocker cover removed and it is clean as a whistle.
Apologies for posting in the wrong section and thanks for moving the thread.
Wow cav551 - you know your stuff. I think I will replace as many pipes as possible. I checked the oil filler cap and it was pretty ■■■■ clean to be honest. I think I may have to dig deeper and take off the rocker hood to have a look.
What are your views on removing / blanking the EGR valve? I know this would increase emissions but wouldn’t it improve air quality?
You will have to be careful blanking the EGR valve, but there is a cheat. You need a resistor on the altitude sensor, thin air conditions disable the EGR system as the engine needs some good fresh air to achieve combustion. I don’t know how many ohms you will need, but there will be an answer on a forum somewhere I’m sure.
Disabling the EGR will solve a lot of your problems, as will having the crankcase pressure pipe not blowing into the engine. Feeding the compressor directly from the atmosphere via an air filter of course, will also improve its efficiency as ambient air will be cooler and therefore more dense than air which has been through a turbo, intercooling helps, but it’s still hotter than ambient.
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To clarify some of the educated guesses concerning th LR TD5 engine. It is a high pressure, direct injection engine. Fitted with an EGR, but if functioning correctly, the recirc valve will only open when the engine is adequately warmed, and under load conditions. So idling shouldn’t cause problems. That said, the manifold pressure switch and thermocouple still get up to the pants in tarry tout. This is sometimes due to turbo seals and the crankcase breather letting tiny amounts of oil into the inlet manifold.
Due to the need for almost zero solid contaminants in the engine oil, which will destroy the engine in much less than 2k miles a year, it’s fitted with two oil filters. One cartridge type, and one high speed centrifugal separator. Generally, the high pressure oil feed is kept very clean. Unlike the sump. 
Has there been any progress in diagnosing the problem with the compressors?