Monarch Brakes

[singapore stag]

Hi All, A fellow Stag ownerfriendhas a slight problem. He has fitted the Monarchs standard 4 pot front and rear calipers and BMW servo. The problems is,... after having fitted the brakes and servo and bled the system the brakes are nice and firm.

When the Stag is started the brake pedal travels to the floor losing all firmness. When the engine is switched off the brakes are back to normal/firm.

Is there something he has missed doing?, Anyone fitted the said system?.

Any thoughts, directions, advice will be much appreciated.

Sukh.

[new to this]

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Can you tell me what brake disc and calipers were used in the rear brake disc kit



you say the brake pedel goes soft when engine is runing have you checked the vacuum pipe from the servo

Dave

[milothedog]

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Just an idea, has he made sure there is a little bit of free play in the pedal travel before the servo is activated, if it's being held forward by the pedal it's going to come on as soon as the engines running because of the depression in the manifold.

Ian.

[singapore stag]

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Thanks for the reply guys, I will forward the suggestions. His car is almost restored now and the only thing holding him back from driving is the brakes.

Sukh.

[V Mad]

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Sukh

I think that because the BMW servo has a greater boost ratio than the stag servo, it is more sensitive to any air that may be left in the brake fluid.

I think therefore that its worth trying again to bleed the brakes thoroughly.

[Guest]

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singapore stag wrote:

Thanks for the reply guys, I will forward the suggestions. His car is almost restored now and the only thing holding him back from driving is the brakes.

Sukh.

I'll bet he can't get the dipstick out ! The BMW servo is too long. He needs to use a Mighty Vac or Easybleed to get all the air out. Cheers, Martin.

[GDPR]

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I have standard discs and drums but BMW servo - bleeding the brakes and pedal feel are quite normal so something else must have been done wrong.

4 pot calipers do tend to displace more fluid, so that may explain a bit more travel.

BTW I can get both my dipsticks out AND in... it would be an odd install that stops that

[Guest]

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kryten wrote:

I have standard discs and drums but BMW servo - bleeding the brakes and pedal feel are quite normal so something else must have been done wrong.

4 pot calipers do tend to displace more fluid, so that may explain a bit more travel.

BTW I can get both my dipsticks out AND in... it would be an odd install that stops that

Hi, perhaps it depends on which BMW the servo/master come from, one of our guys has the conversion, and the engine dipstick is obstructed, obviously he can use it, but a lot of bending and straightening is involved. Martin.