BMC 1.5 Injection Pump Driving Gear Filter, damaged from overheating?

[beanpole]

Hello BMC experts. On a BMC 1.5 engine block on the opposite side from the injection pump resides the "injection pump driving gear filter", as shown on page C4 of the workshop manual. This is a perforated tube about 70mm long with a small nozzle at one end. After an overheating incident, mine had a few small lumps of gauze-like material filling about 1/3 of the tube. What is supposed to be inside this tube, and what is the correct way to clean and service it?

 

I'm worried that some of the filter medium has made its way to the injection pump and may have caused other problems. Due to weeds thinner than the raw water strainer getting inside and blocking the Bowman intake, the engine overheated, over-revved, and then stopped within a second. But that's a different problem. Right now my concern is this filter.

 

[Mikexx]

First of all do you mean this manual:

https://www.asap-supplies.com/media/BMC_Manuals/131000-BMC-1.5-Manual.pdf

 

There are a few different ones in circulation.

 

What do you mean by "injection pump driving gear"? I would normally expect that to be embedded well inside the engine, in contact with the camshaft.

 

I'm wondering if you actually mean the air intake. This is where a picture paints a 1,000 words.

 

Can you post a photo or two. I use dropbox which can provide you with a handy link to share.

[Tony Brooks]

The parts will not be anywhere near the injector pump itself and not be near the drive gear. After the oil leaves that strainer it passes to an oil jet and that would not let broken parts go any further. This oil jet is another hexagon but set vertically close to and slightly below the strainer hexagon.

 

The strainer used to e a tube of brass gauze but for years t has been perforated steel tube so they do rust and fall apart. The opposite end of the tube to the hexagon is fitted with a small cylindrical part with a tapered end to seal the tube. This all need fishing out of the hole. Maybe an airline directed into both the jet and strainer holes might shift smaller parts. make sure the oil jet is clear as well.

 

What do you mean by "injection pump driving gear"? I would normally expect that to be embedded well inside the engine, in contact with the camshaft.

 

I'm wondering if you actually mean the air intake.

 

 

No he means what he says. The 1.5 diesel uses the same skew drive gear on the camshaft as the distributor did on 1.5 petrol engines. I assume it did not prove man enough for the job so requires extra positive lubrications The oil jet I refer to above has a small "pipe" on it that squirts the oil onto the skew gears. The gears are maybe 2 inches away from the end of the injector pump. By the way, re your thread, you had better use the link you gave the OP to find out how to adjust the idle damper on top of the pump. I think that you may have been messing with it by using it to adjust the idle speed.

Edited July 29, 2016 by Tony Brooks

[Mikexx]

No he means what he says. The 1.5 diesel uses the same skew drive gear on the camshaft as the distributor did on 1.5 petrol engines. I assume it did not prove man enough for the job so requires extra positive lubrications The oil jet I refer to above has a small "pipe" on it that squirts the oil onto the skew gears. The gears are maybe 2 inches away from the end of the injector pump. By the way, re your thread, you had better use the link you gave the OP to find out how to adjust the idle damper on top of the pump. I think that you may have been messing with it by using it to adjust the idle speed.

 

Thanks for the info.

 

Yes I had assumed it was to adjust the idle speed!

 

The link I gave the OP is for the 1.5 and I can't find the adjustment process. However:

http://www.asap-supplies.com/media/faq/132000-bmc-1.8-manual.pdf

 

for the 1.8 which of course is similar does cover this procedure.

[beanpole]

Here's a photo of the last hairball I extracted from the strainer. There were about 5 that size, most which came out after a good soaking, air gun, and by pulling at the hairs that were sticking out of the mesh. This last little hair ball required carefully prying open the strainer, removing it with a pin, then carefully closing and re-forming the strainer tube. It seemed to be that the stuff I removed was not proper filter medium, so I hope I didn't just remove something that I should have left in there.

 

 

TB, thank you for the info about the brass gauze. Is there supposed to be anything inside the strainer tube? Doesn't seem like that steel mesh will strain much of anything that one would normally see inside the crankcase oil.

 

Edited July 29, 2016 by beanpole

[Tony Brooks]

Nothing should be inside it. I think its just to stop particles (metal?) from blocking the oil jet. I agree the holes in the steel ones seem a lot bigger than brass gauze but that is what new engines came with.

 

I have never seen anything like what you describe. I have seen browny black residues from a gross lac of oil oil changes and in the worst case it cost a new camshaft and pump drive spindle the teeth were so worn. In that case there was so much backlash in the pump drive it was impossible to time it. Goodness knows where the hairs came from.

 

Please get that oil jet out and make sure it is clear.

[beanpole]

I cleaned the oil jet at the same time, which had no debris. Both are now clean & re-installed with new sealing washers. Oil analysis report came back perfect, with no significant levels of coolant, water, fuel, or metal. I changed the oil & filter anyway, which I've done annually for the past 14 years since the engine was first put into service (that's correct, it's a BMC 1.5 that was in storage until 2002).

 

Sounds like I should get the camshaft, pump spindle, and injection pump innards checked out. I have noticed that the governor no longer governs very well, as the rpm changes more than it used to when shifting in & out of gear.

[Tony Brooks]

As long as you put it back with the master spline in the same position you can draw the pump drive shaft out once you have taken the injector pump off. that will allow you to inspect the teeth on the shaft and if they are OK then a torch shone down the hole should be sufficient to confirm the camshaft teeth are OK.

 

You need to remove the triangular mounting plate from the side of the engine if I recall - 1 countersunk machine screw.

 

I think that there is a thread in the bottom of the socket the injector pump splines fit into, possibly 1/4 or 5/16 dia. UNF. If there is it is well worth screwing a long bolt or studding into it because it will make it far easier to pick up the inner shaft bearing and get it meshing properly with the cam shaft. I has been known fr the drive shaft to drop inside the engine. Failing a thread drive a piece of dowel into the splines. i think a valve grinding stick may be the right size.

 

Use the threaded rod or dowel to twist the drive clockwise and anticlockwise. There should be very little backlash, the more backlash the more worn teeth are likely.