Sump rusted through on ZX

the_weaver · Post by **the_weaver** » 18 Sep 2010, 01:42

It's an M14 x 1.25 mm thread on both holes. I'm going to fit a proper sump plug to make sure I've got the right thread type.

If it's bare steel then that's a bit worrying. It might rust worse than my old one unless I do a good paint job. I've got some Hammerite smooth, but when I used that on a small bit of the roof, it came off after a couple of years. I did a good job of preparation as well. Since then, I've heard some discussion about Hammerite not being as good as it used to be, because they took the solvent out. How hot does the sump get? Do I need special paint for hot areas? I remember seeing paint designed for cylinder heads on motorbikes. Would that stand up to stone chips though? Maybe I should just underseal it.

Paul

Post by **myglaren** » 18 Sep 2010, 08:41

Powder coating would be best IMO but it isn't a DIY proposition.

Xantidote · Post by **Xantidote** » 18 Sep 2010, 10:34

On the basis that you're not going for concourse, and that the new sump will outlive (?) the rest of the car, I'd clean off with solvent, perhaps finishing off with acetone/paint thinners, and then applying a spray of primer from the many aerosols I seem to acquire, followed by 2 coats of whatever colour hammerite I can find in the garage.

Doesn't have to be black. Can always touch it up at a later date, if you can be bothered. Any paint job will slow down the sump rust

Old-Guy · Post by **Old-Guy** » 18 Sep 2010, 16:48

Personally I hate powder coating. That on my admittedly 14 year-old tow bar was coming off as the top layer of huge thick flakes of rust. In my experience, powder coating is often applied to inadequately prepared surfaces. Corrosion is hidden until it's got so bad that it splits the coating, letting in more water to make matters worse.

It's a process ideally suited to volume manufacturing - a fast, easy, solvent-free, means of applying a thick(ish), good-looking, surface coat that will take the knocks of distribution. It will hide surface corrosion that won't become evident until after the product has been sold, is out of warranty and is the customers problem.

When I asked the manufacturers about using hammerite on a domestic radiator, I was told that Hammerite is suitable for continuous temperatures upto 100ºC - above that it becomes increasingly soft.

the_weaver · Post by **the_weaver** » 18 Sep 2010, 21:58

On the tin of Hammerite I've got it says: "5 Years Protection". Maybe I'd be better off with normal car paint in aerosols. It doesn't say how long it lasts for, but when you do a body repair on a car you don't expect to have to keep repainting it. I know the cellulose car paint they used to sell in tins for spray guns was quality stuff, that lasted for years. I'm not sure about the paint in aerosols though.

Paul

dnsey · Post by **dnsey** » 19 Sep 2010, 11:06

Why not use an anti-chip paint? I don't know what its maximum rated temperature is, but a sump doesn't get that hot anyway.

the_weaver · Post by **the_weaver** » 19 Sep 2010, 22:17

There's only one motor factor within walking distance from me so I'm going to have to use what they've got in stock. I'll see if there's any anti-chip paint there. I looked on a tin of underseal I've got, and it says not to use it on sumps. What temperature do sumps get to? Proabably the same as the oil temperature but I don't know what that is.

I've been wondering if the sump might be made from stainless steel. Screwfix can sell stainless steel sink units for 50 quid so it's possible that a sump could be made from stainless steel. The sump looks a funny colour for mild steel, but it does look similar to the underside of a stainless steel sink unit. Either that, or it's plated with something. The sump has been supplied completely unprotected, not in a bag, or in a box. Normally, when you buy anything made from steel, it comes with a protective coating of oil or someting to stop it rusting in the stores. This has nothing like that.

Paul

JohnD · Post by **JohnD** » 20 Sep 2010, 09:17

If it's bare steel I would use bitumen paint. Screwfix have it:-
http://www.screwfix.com/search.do;jsess ... button.y=8
Only paint the outside up to where the gasket will sit. Give it two coats with six or so hours in between coats. At first it will stay shinny but eventually it will dull down. It will also withstand knocks.

Xantidote · Post by **Xantidote** » 20 Sep 2010, 10:20

I very much doubt it'll be stainless. My money's on mild steel. - difficult to tell from piccy whether it's been electrplated. You could use a magnet to check. Mild steel is magnetic, whereas only a few grades of stainless are, and then not as strong a pull as mild steel

Your getting lots of options for the paint job - they'll all work to varying degrees. It'll be a compromise of what's available at your local factor, cost, and ease of application. Once you've done the job, you'll forget all about it

the_weaver · Post by **the_weaver** » 20 Sep 2010, 23:59

I tested the sump with a magnet, and it sticks, so it must be mild steel. The magnet doesn't stick to my kitchen sink unit.

I found this video of a chap in an American Bodyshop telling you how to paint a sump:-
http://www.ehow.com/video_2327476_paint ... l-pan.html

He's says that normal lacquer doesn't last long on sumps. He's using American terminology, so lacquer doesn't mean clearcoat - I think he means Acrylic Lacquer, which is similar to the Acrylic aerosol spray paints we have here. He uses self-etching trim paint. This seems to be a harder wearing paint for use on metal door surrounds, metal bumpers etc. It's probably matt black, if it's the stuff I'm thinking about. He says that etching is important to give the paint the best adhesion to bare metal. I'm not sure if I can get the all in one self-etching trim paint here or not. However I can have a look for some etching primer and then put a tough trim paint on the top, depending on what's in the motor factors.

Paul

the_weaver · Post by **the_weaver** » 07 Oct 2010, 02:40

The sump is now painted and ready to fit. The sealant I've got is from Citroen, which is made by Loctite, with the price bumped up by Citroen. The problem is the lack of instructions (a few sentences) with the Loctite, and the fact that they're in French. The Loctite product is Loctite Silicone (grey) IDH number 1140455. I think it's a French product as there isn't much information about it on the web. The British Loctite numbers seem to be different. There is still no useful information with regard to sumps in particular. The Loctite product seems to be a general purpose thing, so they don't give you specific instructions for a sump.

All I've worked out so far is - Assemble parts straight away, as it starts to cure as soon as it comes out of the tube. Allow time to cure before subjecting to load/stress. Follow manufacturer's instructions as to where to apply it.

My questions are:-

How long do I need to wait before putting the oil in, and using the engine?

Do I put in on the sump and the block, or just one surface?

Are there any special instructions from Citroen about where to apply it on the sump joint face. I was going to spread it all over the flat part, which is about an inch wide, (as it's not painted there) but I suppose there may be a reason not to apply it in certain places. It's not a good idea to allow stuff into the oil, as it might block up the oilways in the engine. So maybe I should only put a thin line of it? Should I use the whole 100ml tube, or is that enough to do five sumps or something?

Paul

VertVega · Post by **VertVega** » 07 Oct 2010, 07:56

Check this link if this is the same product you bought (pic and descr.)
--> Halfords, Loctite 5699 Premium Silicone Grey
and here's a pdf file --> Technical Data Sheet Loctite 5699

It says in the directions for use:
....
3. The bond should be allowed to cure (e.g. seven days), before subjecting to heavy service loads.
_____________________________________________________________

Edit: from French Loctite (Solutions d’Etanchéité Mécanique),
Same product (5699) have these numbers
Tube 100 ml 1140455 (IDH N°)
Blister 40 ml 1124089 (IDH N°)

the_weaver · Post by **the_weaver** » 08 Oct 2010, 01:44

Thanks for the info Vert. It's probably the same stuff. The seven days curing time is a long time, but that's for thicknesses of 8 mm or 10 mm. It cures quicker for thinner gaskets. I'll give it as long as I can, probably one day. The curing time for the black stuff (5910) is similar to the grey stuff, so there's no point in looking around for something else.

It doesn't say whether to apply it to one surface, or to both surfaces.

Paul

P.S. - Just noticed the info in your edit. Useful to know it is the same stuff then.

the_weaver · Post by **the_weaver** » 10 Oct 2010, 02:08

I've removed the old sump. I checked the service.citroen site, with my car's RP number, and the car should have had sealant on the sump when new. Now I've removed the sump I can see that there's a gasket there. The sump has never been touched since new, so that's the original gasket. I'm going to use sealant with no gasket. Is that ok? There's no problem in swapping between gasket and sealant is there?

The old gasket is stuck to the block. I've removed some of it using a Stanley knife blade, but it's a long job. Is there any easier method of removing these gaskets?

Paul

jgra1 · Post by **jgra1** » 10 Oct 2010, 08:56

hi Paul, interesting about the sealant... i wondered why it was on mine when I removed the sump 2 years ago.. at the time I did not realise the factory had put it there.