egr pipe repair

[RaceDiagnostics]

£150 or so for a new one of these, so does anyone think that this can be repaired?

 

[Woody.v8]

Yes they can be welded, Although not ideal ive done a few.

 

[premmington]

Yes they can be welded, Although not ideal ive done a few.

I have welded a few up, DC TIG low amps, I normally use a 309 rod!

The more carbon you can get out of the inside, the better!

 

[RaceDiagnostics]

whats it from?
I took mine off (went porous...) and blanked the manifold end and the turbo end...

Its off an XK8, I think it will throw a trouble code if I try that.

 

[Tigman]

I would close up the bellows and weld the first two together all the way round !

 

[RaceDiagnostics]

Don't have a TIG but I am close to http://pipedynamics.co.uk/ so could ask them to have a look.

Do you think that brazing with a MAPP torch would be successful with these rods?

http://www.diy.com/departments/gosystem-brazing-rod-pack-of-2/196541_BQ.prd

 

[RaceDiagnostics]

Thanks for that, it is applicable to the 4.0 engine, I wonder if it is also applicable to the 4.2? I'll ask around on the jag forums.

 

[Bill Edwards]

You might manage to braze it with MAPP, but I think you'll really struggle - I've tried with propane and found it to be pretty much a waste of time. I know MAPP is hotter but I doubt it'd be easy. But the problem with brazing, regardless of the fuel source, is getting it clean.

I'm not a TIG man and can't comment on how that process would fare, but it would certainly gas weld.
Or you might get away with losing the first bellows and could therefor probably blast in with a MIG...?

 

[Woody.v8]

You could get it with mig but with mid steel wire im not sure how long it would last.

 

[dannyp]

burn the carbon out of it first, ether with propane torch or even better oxy something with reduceing flame just dont melt it.

it'll weld with mormal mig wire just fill the trough up

 

[gordon stephenson]

X2 for brazing,

 

[brightspark]

x3 for brazing best with oxyacetylene torch though. if u were local id have done it for u cos im bored with nothing to make

 

[AndyStobbs]

Does stainless steel braze nicely?

I would cut the parallel tube off, then cut the last bellow off, weld the tube to the second below.

 

[dannyp]

good question well asked, thats something i'm going to have to try just to see what happens

 

[brightspark]

u can braze -stainless steel no bother; just give it a good clean 1st, it will be a doddle to fill that in

 

[ukracer]

u can braze -stainless steel no bother; just give it a good clean 1st, it will be a doddle to fill that in

What actually is brazing as opposed to welding. A bit like glorified soldering?

 

[RaceDiagnostics]

These will braze with the MAPP gas I have -

This GoSystem brazing rod is suitable for the joining of mild steel, stainless steel, brass, bronze and copper with a maximum temperature of 750°C, and a minimum temperature of 650°C.

...but it might melt out under an extended WOT, I used to go over 1000degC on my TT, but am not sure of the max temps on the N/A 4.2 V8.

So TIG may be the better option unless I can find someone else locally who can braze with something at a higher temp.

 

[brightspark]

soft soldering silver soldering or brazing. just a -higher temperature melting point for silver then brass and stronger joints. brazings best on steel as its cheaper on rods, silver solders best on brass or copper as it has a lower melting point and wont-melt -your job

 

[Turbo]

If you can at all blank it off. I've yet to hear of an EGR system on any car that works properly, especially after it has done a few miles. They get gummed up with soot & oil and cause no end of problems.

Simplest way to blank them off is to copy the gasket in thin steel but without the central hole then fit it between the flange & engine with a gasket either side. I've also heard of people using a copper coin to blank the hole!

You might also need to disconnect the air pipe off the EGR valve itself & blank off the pipe, depends on the system.