11 replies to this topic

[Terry1987]

How much rust can a boot floor have before it becomes an MOT failure???

Which exterior panels would rust prevent an MOT pass

[Simont]

all depends on the location of the rust on the particular panels

[Terry1987]

all depends on the location of the rust on the particular panels

Yeah I know, that's what I'm asking lol...

[minimissionary]

Tends to be structural things. Anywhere something is mounted to, or holds weight, or would protect you in the unfortunate event of a crash.
To be frank, if you can cover it with paint and a screwdriver won't go through, then it'll be ok for the MOT. It'll only get worse though, and for the price of the paint, you could get a piece of fresh metal welded in.

[Terry1987]

just a little bird told me that a hole in the a-panel would fail the MOT

[minimissionary]

£15 for an A panel. A panel rust can mean scuttle and A pillar rust.

[sonikk4]

If its within 300 mm of a hard point ie subframe mount or seat belt mount then fail. If there is a hole in a wing and it has sharp edges then fail. Hole in the floor fail. Holes in inner or outer sills, fail and so on.

However when you see some of the posts on here then there's all sorts of different areas that fail due to rust other than just these ones. I think a lot of it is down to the tester in question. If you are not sure with rust a quick test is to see whether you can push a screwdriver through it.

Other people may say differently but as a rough guide then most of the above is pertinent.

[tiger99]

There is no fixed panel which is not stressed in the Mini, or any other properly designed monocoque, however some are carrying primary stresses and others are mostly bracing the panels which carry the primary stresses to prevent buckling, so structurally speaking, they all need to be there and fit for use. A few small holes in secondary panels will not make the structure fail, not for many miles anyway, but no hole in primary structure is acceptable.

The MOT is not actually based on what is safe or unsafe, which is rather complex, and different for every type of car, but on what can be tested reasonably easily, while attempting to catch most dangerous problems. There are places where you could have a hole quite near to a suspension mounting without endangering the structure, but a definite MOT fail, and others more than the requisite distance from any suspension mounting, seatbelt, etc, which would make the car a deathtrap, but might pass the MOT.

A hole in the A panel is a MOT fail, on the grounds of jagged bodywork, and as it is quite close to the most highly stressed part of the Mini shell, a good tester would fail it for that too.

Hint: Find the thickest pieces of metal on the Mini. and you will be close to the most highly stressed areas.

[tommy13]

You must define what you mean by rust. The corrosion must have progressed to a state where it has resulted in a hole or sufficiently thinned the metal so tester can push his finger or thumb through to make a hole.(stabbing with a screwdriver is not allowed)
In the boot of a Mini the floor must be sound within 30cm of the rear subframe mountings and also the rear lower seat belt mounts. Corrosion of the battery box bad enough to compromise the security of the battery will also fail.
As a matter of interest, shock absorber mountings are not counted as load bearing points unless the suspension spring is part of the shock absorber. The shocker mounting can be quite rotten, but providing the shocker still functions and the rot does not fall into the prescribed area (30cm) of ather component, then it is an advisory matter.
If you are still unsure, some photographs of the rust will help.

[Terry1987]

Thank you, all of your replies have been quite helpful...

[tiger99]

Even if that is true about damper mounts, which I seriously doubt, they should be an automatic fail on a Mini, because the damper is the only thing restraining suspension droop, and if it is becomes unattached the knuckle joint can disengage. At the rear that causes an immediate suspension collapse, with the wheel locked tight against tha arch, and we all know what Minis do with locked rear wheels. At the front, knuckle disengagement is less likely except on a lowered car, but if it does happen the inevitable collapse will sheer the bottom ball joint, at the very least, causing loss of control. At the front, it may be corrosion around the damper mounting, but it is often the lower damper pin which snaps, and even in 1970 they were failing Minis for that.

The more competent MOT testers will know that, and will fail it.

[Terry1987]

Hint: Find the thickest pieces of metal on the Mini. and you will be close to the most highly stressed areas.

That would be the tin foil wrapped around my sandwiches in the boot! lol

You know what, for s**ts and giggles I think I'll put it back together when it arrives and cook it in for an MOT