drivers chassis leg

[grainger]

hi

i had my passenger side chassis leg replaced a couple of years ago now it looks like the drivers side is going .. anyone tell me if its going to be possible to patch it up or is it going to need cutting out and replacing ?

cheers
grainger

[rayofleamington]

If you're keeping the car, then patching it isn't the best way forward (patches on a chassis leg are only really a temporary repair as the rest of the leg is likely to be getting thin also).
If the rot is within a few inches of the eyebolt then I would recommend not to get it patched - most of the eyebolt strength comes from the strengthening piece inside the leg so patching this area may give an MOT but also gives the risk of the lower suspension parting company from the car.

[grainger]

it has a little hole underneath where the master cylinder must be, i havent tried to see how far the rot goes yet ... i want to keep the car as long as i can so it will have to be done properly one way or another

thanks
grainger

[chickenjohn]

I agree with Ray, best to replace the whole thing, but if its only one hole and you can get access to both sides to check how far the rust has spread then yes, you could let in a patch, although you may need more in future.

Hows your welding going Grainger?? and hows thw music??

[grainger]

hi john

the musics going better than the welding to be honest ! .. (just got a couple of lovely joe meek threeq's that im getting the hang of)

i dont think i would dare try to replace the whole leg myself and i can see its such a fiddling job it will be quite expensive to get it done in the garage ... maybe if i patch it up till ive got a bit more experience, anyway im not sure if my 100 amp mig will be up to the job ?

ive been hitting the leg with a hammer and i think the rot is probably just within 6 inches under the master cylinder .. the section round the eyebolt seems ok but i think i'll hit it some more to make sure

cheers
grainger

[chickenjohn]

Hi Grainger,
sounds like you can get away with it in this case! Just cut the rust away and weld in a new piece, as you say, its the eye bolt area thats crucial, as there are internal stiffening plates and a tube that the eye bolt goes into that cannot be repaired by a patch.

But to get through the MOT, for now, it sounds to me like you can get away with it.

It would be perfect to build your confidence in your welding!

I would remove the master cylinder (be careful, brake fluid is highly flammable) and clean the area on the inside as well as out to bare metal, then do a lap welded plate with a small overlap (5mm, or 1/4 inch) between the patch and plate weld from the outside. You can then paint inside and out of the repair with zinc primer/ hammerite to protect it.

Re-fit the master cylinder and job done.

(Unless that is you're more confient with your welding, in which case a butt weld, then grind smooth to the surface of the leg could make an invisible repair when painted ;) )

My music is going well too! I've been using my new ADA8000, with the MOTU896 to record my bands demo, 14 track recording!!

Good luck with the car repairs!!

[Cam]

(be careful, brake fluid is highly flammable)

This is a common misconception. Brake fluid is NOT flammable. It usually just smokes when welded through. We had this discussion before on this messageboard and I could not get a sample of the fluid to ignite at all! But Bigginger managed to light a an amount of it with a blowtorch but it just burns very slowly.

In fact I found an article on the internet from an oil producer stating that brake fluid was classed as not flammable.

Of course you should always be careful when welding anyway, but don't be afraid of brake fluid (unless you get it near paint! )

[grainger]

I would remove the master cylinder ....!!

thats what i thought youd say :oops: ... course it WILL have to be removed but im not looking forward to it. im going to spend some time under there this weekend ... the torsion bar has to be undone to get the master cylinder out, dunt it ? ... in the end when ive stripped everything i may well end up being able to do the whole leg

what about the 100 amp welder ? ive only used it on floor repairs so far - i can borrow a bigger one if i need it ?

My music is going well too! I've been using my new ADA8000, with the MOTU896 to record my bands demo, 14 track recording!!

... i read your ADA review at sos sounds good, im getting a behringer src2496 ad/da - amazing versatile box for very little money, arent behringer brilliant ? .. hope yr demo goes well, my sons band paid to go into a studio in stoke in the end - 10 tracks in 2 days !!! amazing what you can do when yre paying 20 quid an hour !!

cheers
grainger

[Cam]

The 100 amp welder should be fine for a chassis leg.

[grainger]

oh cam (long time no see - hope you are well)... that would make it easier if i didnt have to take the cylinder out .. is it just an urban myth then or what ? .. i remember that programme where they said more fires after head on collisions were caused by brake fluid leaking onto the manifold and self igniting ... is it very volatile when its hot or something ?

cheers
grainger

[Cam]

Hi mate, yes I'm fine thanks!

Well, looking at it logically why would they use VERY flammable fluid in brake calipers that can get VERY hot with glowing brake disks/pads!!!

If it's a temporary (1 or 2 year) patch then you'll probable get away with not taking the cylinder out or moving the torsion bar. Of course it's not the perfect thing to do but bear in mind that if you DON'T take the cylinder out then you can't protect the inside with paint/wax/etc. It will probably rot through again in a couple of years, then you'll have to replace the leg (if you wish)...... I have re-patched before now when time and MoT was an issue, but it's only putting off the inevitable......

Still, it gets an MoT though!

I have welded through brake fluid a few times and it just smokes. But if it DID catch, then just beat it out. In my experience, underseal and paint catch fire FAR more easily than brake fluid.

If you are in any doubt then try to set fire to some away from the car on a concrete slab or something just to prove it to yourself.

[rayofleamington]

This is a common misconception. Brake fluid is NOT flammable.

Brake fluid is flammable - at least some of it is as I've seen it done (on telly).
After your attempt to set fire to it, it seems that not all brake fluid is flammable, but I wouldn't want anyone to kill themselves thinking it was impossible to set fire to it!
The reason it is used is that mineral oil seals can NOT suurvive the temperature range needed in brakes - you can get mineral seals to survive high temperature but typically these leak at low temperature.
EPDM seals will do high and low temperature, hence brake fuid is better for brakes.

[bigginger]

For what it's worth, here's the link to the film Cam mentioned -
http://www.nogginthemog.com/images/fluid.mov
Reasonably big/slow download, BTW

You can remove the M/C without taking off the torsion bar if you use a lever to bend the bar down so that you can get at the nuts/bolts (depending which way round they are) - put the nuts on the torsion bar side when you re-fit, then you never need to worry again, 'cos you can slip a spanner betewn the chassis and the bar to undo them, and removal is not a problem

[Vernon]

This may be of interest:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 75500&rd=1

The description is a bit confusing though!

[chickenjohn]

Whether or not brake fluid is flammable is getting somewhat off topic (sorry if I'm wrong, that was from Rob Thomassons article on the club manual). I've never tested the flammabillity myself but if I'm giving advice on an internet forum, I prefer to play safe, for example, while I have welded near a petrol tank (with suitable precautions taken) I would definitely not reccomend doing so to someone else.

One thing that worries me is that brake fluid in a chasis leg full of crud may very well be flammable- best to clean the panel before welding, of everything- dirt, rust, paint, brakefluid, oil, everything.

I've tried the bending of torsion bar method to remove the brake master cylinder but to be honest, found it easier to drop the front suspension. Its a good opportunity to change the bushes at the time, and with the eye bolt out you can have a good look at the soundness of the chassis member in that area too.
And get the bolts back in the right way round- in my case the ends fouled the torsion bar, so i had to drop the suspension anyway! Next time I'll just remove torsion bar and get on with it.

<warning! thread hijakck!> Grainger- I can PM you a link to tracks I've recorded recently, if you like! Yes Behringer stuff is underrated and gets an unfairly bad reputation on the SOS forum. (sorry for OT hijack!) ;) I think all you did wrong on your sons bands demo was to place the mics too far away- modern bands expect the close mic's gates compressed and EQ's sound </-hijack over->

I too would think your 100amp welder should weld chassis material ok, might need to turn it up to one of the higher settings though- and practise on plenty of steel of the same thickness before hand- clean degreased unpainted steel.

My thinking behind removing master cylinder before welding is two fold-

1 safety, to avoid fires, as mentioned.
2, to be able to paint the inside of the repair thus prolonging the life of the repair.

You might be lucky in that the chassis leg is basically sound as the only reason it went near the master cylinder is because dribbles of brake fluid stripped the paint exposing the bare steel to the dreaded red stuff!

Just my thoughts. As usuall on web forums, read the posts and take with big pinch of salt!!! ;)

have fun! (well I do when i'm welding in metal , anyway!)

[bigginger]

Whether or not brake fluid is flammable is getting somewhat off topic (sorry if I'm wrong, that was from Rob Thomassons article on the club manual).

Don't know the dictionary definition of flammable, but it *does* burn!

I've tried the bending of torsion bar method to remove the brake master cylinder but to be honest, found it easier to drop the front suspension.

Never had a problem - much easier than dropping suspension.

Do take it all with a sack of Saxo, though it might be worth giving it a go before dismantling half the car.

[chickenjohn]

To clarify, Bigginer, I did use the "bending of torsion bar" method to get the master cylinder bolts out, but on reassembly, putting them in from the other side, unfortunately the ends of the bolts fouled the bar.

So I dropped the suspension (takes less than an hour if you've done it a few times ;) ) and put the bolts back in from the torsion bar side before re-assenmbly of suspension.

But if it works for Grainger then it works.

and hope fully, we havent put him off DIY repair!

[bigginger]

Hear Hear - and good luck to him! Not trying 'to make a point' BTW, in case I offended you...

[chickenjohn]

No probs mate, I just thought I hadn't explained myself well enough!

BTW, I've just spent an enjoyable (!!?) evening stripping underseal and rust from the inner rear wing of my traveller- welding of a few patches tomorrow!

[bigginger]

...and I spent an unenjoyable few hours trying to shift the gearbox drain and fill holes - +^&%$£@! I'd guess no-one has for a few years... Better get a socket or 2 for the impact driver tomorrow. Is that you in the picture/URL after your sig, BTW?
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