kyk007

Hello one, hello all. I'm a fledgling member, but each time I log on I find out another tidbit about our cars that endears me to them. OK, onto the topic at hand.

I am in the process of flushing coolant from my system (last owner used the dreaded 'green' coolant). I tried to read up on the proper way to do this in order to keep air out of the system when refilling. Here's my dilemma.

I located my filler plug, and according to other posts on here, it's supposed to be a 10mm allen wrench that fits. I don't quite know what alien changed out mine, but it more closely resembles a Torx T-55 bit, only it's more rounded. Unless I am completely spacing on this, it's a strange situation to say the least.

My question to you all is this: do you know what type of bolt head I might be referring to, and if so, have you encountered the same? Secondly, if by chance no one has any idea what I am talking about, can I safely refill my coolant (without introducing any air pockets) by another method?

Any and all feedback is greatly appreciated in advance. Thanks to everyone . . .

sha4000

iTrader: (1)

I believe those drain ***** on the side of the engine are either 12mm or 14mm.

randal

Well it could be stripped out (rounded) but it should be a 10mm allen, not a torx. I bought a bit to fit my 3/8 in drive ratchet when I refilled my system. I suppose you could slowly fill and let the reservoir suck the fluid in over several heating/cooling cycles but I would really recommend filling from the 10 mm port at the front of the intake.

randal

The 10mm fill plug is at the top-center of this pic. It is a 98 LS400.

timmy0tool

iTrader: (7)

this is for a 1st gen but should be similar.
http://www.lexls.com/tutorials/cooling/coolant.html

i don't think he is referring to the drain ***** on the side of the engine, but rather the filler plug which should be a 17mm bolt on 90-97 cars. it's different on the 98-00 cars. see attachment.

sha4000

iTrader: (1)

My mistake for some reason I read drain *****. Randal is correct that the filler plug is allen key and not a torx which is why is seems more rounded. The torx is a star pattern and the allen key is more rounded. The top pic are torx bits and the bottom is an allen key.

randal

It is in a similar position but is not a 17mm bolt like the first gen. It is an allen bolt.

kyk007

Hello gentlemen: thank you all for the timely input into my problem. Everything you say is spot on. I researched up the wazoo the different bolt head configurations out there, everything from Torx to allen to polydrive. And you are correct - the bolt head is supposed to be an allen head, however, mine is more akin to a polydrive, albeit it a bit rounded. (it does have 6 sides)

That leads me to believe the previous owner stripped the head. Randal & TimmyTool, thanks for the pic and the diagram. That matches my observations and findings as to the proper location for the filler plug.

Now to the problem at hand. How to remove the filler plug bolt? I added coolant flush to the system today, along with distilled water. I will drive the car a day or two, and then drain it. I bought the Toyota red coolant to add back, so that is my plan.

From all I have read, adding coolant through the filler plug is indeed the surefire way to avoid air pockets, so you guys are obviously in agreement here. Any ideas on how to remove this stripped out bolt? I know, that's a separate question unto itself, but I would welcome any input.

Thanks again for all your expertise and feedback. It is much appreciated.

randal

First, I would want to buy a new filler plug. Then how to remove the old one?

Here is what I would try in descending order:

1) Get a pair of large vice-grips on the outside edge of the bolt. There is a small shoulder showing. Grab that.
2) Find the next highest Torx bit that looks like it might fit if you pounded it in. Then wedge it in there and turn. This will most likely trash the torx bit.
3) Use a sharp pointed chisel or punch and tap on the top edge surface of the bolt in a counter-clockwise direction. As the punch 'bites' into the metal, it should begin to move.
4) Use a two-part epoxy and cement in a sacrificial allen tool overnight. Then remove.You will of course, trash the allen tool.

kyk007

Randal - all good suggestions on what steps to take next. I had given some thought to 'sacrificing' an allen wrench or a second bolt by using a two-part epoxy as well. I appreciate you posting the link for the filler plug. As you say, I should concentrate on finding a replacement filler plug, and then proceed to removing it after that.

Thanks again for the timely tips.

kyk007

Randal, I will display my ignorance by asking this question, but the link you sent for the filler plug - is that the actual size filler plug that will fit my '98 LS400? Or perhaps it is a different size . . . pray tell.

randal

I am not sure what you are asking. I did not post a link for a filler plug as far as I know. There is a picture of the engine with the plug.
You are probably going to have to go to the Lexus dealer for a new plug.