Thread: Super annoying low coolant alarm going off until car warms up (earth issue??)

Originally Posted by BathurstTom

.... That plug is perfectly round. Looks like it was made that way, not butchered.

Tom.

Yep definitely the design. Absolute annoyance to remove, especially on the radiator where sideways space was limited.
At least on the thermostat housing you've got lateral space to remove it 'easily'.

Could use a regular screw driver fitted sideways across the entire gap section and 'lever' it off .. but as I said, best that once removed, have the replacement part ready.

I remember eventually getting a tool to remove it, got at a hydraulic/hose type store(like an Enzed). Was a socket like tool with bar at the end to fit into the cavity section.
Like a box spanner used to remove tap valves kind'a thing.

My D1 had the plastic bungs, which I removed almost immediately at the earliest opportunity.
I got a massive stainless 1-1/16 hex nut for the rad, but the brass 3/4 hex nut with the 1/8th NPT access for my sender. Got from a local hydraulics shop.

Mario probably sells replacemnt brass hex plugs.
I think i got mine on ebay
Do people use o rings on these?

The slot is pretty butchered though

Originally Posted by trout1105

I am just hoping that this plug isn't indicative of the quality of the work done on your truck by the PO or the mechanics that you have been using.
Why wasn't this addressed when you had the work done on your cooling system recently?, Any fitter that is worth his/her Salt would have replaced that abortion in a heartbeat.

Well I didn't get a new thermostat housing, just the thermostat and the P Gasket. That plug must just be what I had in there before so I might ask him for a replacement. Not sure why they didn't replace it to be honest, but oh well I'll ask them if they've got something a bit better, and if not I'll just get one from Mario and rip this one off with a set of vice grips!

Originally Posted by trout1105

....
The amount of use this plug has had leads me to think that there has been an ongoing problem where the system has had to be bled an a regular basis.

I wouldn't put it that way.
The plug is brass, and even only one or two removals can easily damage it as it currently is.
It's dependent in the person removing it and what tools they have available to remove it with.

From experience, it wouldn't surprise me if it's only been removed a few times, but as you said, butchered in the process .. but I reckon due to a lack of available tools, more so than the number of times it's been removed and refitted.

What doesn't, and wouldn't, make sense is that if it were butchered due to being removed often because of ongoing issues, that at some point in the extremely difficult removal process, the person would have changed it for the more sensible hex head type!

Under normal circumstances I wouldn't describe myself as sane, but only an insane person would persevere with a plug of that design in an ongoing situation and not consider an alternative plug type.
Back in my RRC days, I remember difficulty in getting these back on, so even for an 'insane' person such as myself enough was enough and a better solution was sought.

Having been told of a brief history of Ben's D1, it seems very unlikely that the effort that the previous owner to maintain the vehicle, that they'd have persevered with that plug if there was an ongoing issue.
Ben's had the D1 for a good number of years now, and hasn't relayed any ongoing issues of that type either.

The reality of the situation is simply down to a few basic points. The plug is brass, which is soft. It's an extremely annoying design, for which hardly any tools exist for it, and the 'operator' will usually resort to some cobbled up tool/s to remove and refit.
In that process, the tool will almost certainly slip the first attempt, so the operator then has to get a feel for what operation style might work .. and they'll probably slip for that modified attempt too.
By this second attempt, it's guaranteed that the soft brass edges of the slot have been butchered, and will only get worse now due to the wear and additional attempts to remove or refit.

Originally Posted by Young Angus

Tell me about it!! They are supposed to be a hex on top though anyway aren't they?? I've never seen a round one in any pics or videos, I mean even if I ignore the damage that has been done to that plug it doesn't look like it was ever easy to get off!

I use a 2ish mm (whatever the slot size is) piece of steel that i cut. Bout 4cm x 2cm. Could be any size. You put it in slot and use adjustable spanner or similar to open it. My radiator one was round like that. I now have one with slot and hex.

The thermostat one had hex but now has my coolant alarm plastic bung on it with rounded edges coz somebody decided to put sealant all round thread when they fixed a leak in my radiator.

Actually now I remember. The steel plate i cut is smaller. Still 2 or 3mm thick but small enough to fit inside one of my sockets. I think bout 3/4 inch socket. You slide plate into it, then clip socket onto breaker bar and put it into slot on bung and turn. Works like a charm.

OK
Young Angus has told us that truck has been leaking coolant from various parts of the cooling system so there is Most likely less than the optimal amount of coolant in the system now and the (faulty) alarm is Most likely working perfectly.
He also said that he has trouble tightening a hose clamp on the water pump enough to stop it leaking, I suspect a corroded water pump inlet is the culprit here and hopefully this is what is causing the coolant loss.
As the system needs to be bled anyway it wouldn't hurt to remove the hose from the water pump to inspect the integrity of the metal for corroision/holes and to see if this is the problem.