400i Brake Booster not functioning after complete overhaul from F400 Club member

It would be surprising if the problem is they booster itself as they are a very simple device (but a little tricky to take apart). In any case;

For LHD, there is a different part number shown for 400 auto and manual - The 400 manual is the same part number as 365GT4 2+2 (124518) but with different plastic reservoirs. The auto shows part number 110792.

For RHD, there are different part numbers shown - these have a different orientation for the vacuum hose fitting to put the hose high and on the outside. The two 365 and one 400A RHD's I have owned (plus all others I have seen) have had the LHD variant mounted inverted (so the fitting is low on the outside) from new.

I have recently had a 365GT4 (124518) and 400A (110792) boosters and master cylinders apart for resleeving and replating and they are identical.

The master cylinders for all are 1 inch diameter (not 25mm).

Hope this helps.

WM

 

Jean-Michel,

It is only 2.5 hours by air to Noumea from here - a very nice place that I am looking forward to going back to for sailing.

If the brake pedal is hard with little pedal travel (and with the engine not running), it is likely that the hydraulic circuit is o.k. and the problem would seem to be the vacuum circuit/booster.
Check that there is vacuum at the boost by taking off the fitting on the booster. Sometimes old vacuum hose can collapse internally and block the hose.
If there is vacuum at the booster, then it is possible the booster is damaged. The major moving part is the rubber diaphragm which is not available as a spare part (as far as I know) but both of the diaphragms I have seen have been in excellent condition and normally would not need replacing. Damage during repair is possible. There is also a shaft seal that is available from Superformance (and probably other suppliers).
Regarding the master cylinder itself, a seal kit is available from Superformance and there are many shops that do resleeving with a stainless steel sleeve (although maybe not in New Caledonia). Cost for sleeving here is about USD90 plus assembly if required.
It would be possible to have the master cylinder serviced in Australia, but import and export regulations in both countries, might make it tricky.
Regards
WM

 

As for the export/import duties, I do not remember the exact custom rules for this -still- French overseas territory but should not be worse than for the metropolitan area. There is a specific procedure for repair services, in order to be charged only for the repair and not for the full cost of the part as it crosses borders. It normally involves directly getting in touch with customs at your local airport, filling the proper paperwork and then request your seller to send directly the part back to airport custom (not your door!). Most local carrier (eg: GLS) are not familiar with the procedure so they never apply the proper tariff, hence the need to liaise with the custom desk.

"livrer en douane" is the magic formula in order to pay the fair custom tariff. That's how my SwitchPitch TH400 used to travel across the Atlantic...

Not sure how the process has evolved recently, but this owner should liaise with custom in any case: owning a 400i in New Caledonia is quite a challenge so he'd better be good at sending (and getting back) parts across the world!

 

Hi Jean Michel & Bill

Thank you very much for your help, in a first time I will order the signal valve pressure difference to change it, but I'm afraid it's the faulty booster

I will keep you informed of the progress of the repairs.