New master cylinder + booster = worse brakes?

**chillman** · 13th April 2018, 02:24 PM

I got my local Midas to install new master cylinder (mine was leaking badly and I didn't have time) and a new booster on my 98 V8 D1. When I picked it up and they said the brakes were worse and they couldn't improve them.

The pedal is so spongy any attempt at braking and the pedal hovers just above the floor and there is almost no braking. First thoughts was that it wasn't bled properly, they swear they put nearly 2ltrs through it.

The pedal drops if I pump it, hold, then turn the car on which I thought showed the booster is working.

Assuming they did bleed it properly is there anyway they could have mis-installed it or broken something when they did? Wanted to check before I go ahead and bleed it myself.

**JDNSW** · 13th April 2018, 08:35 PM

I'm guessing they have installed a wrong part or have omitted a spacer, or got the adjustment wrong on the piston rod, or a combination of these. It could be just air in the system, but I doubt it. Returning a vehicle with brakes in that condition does cast severe doubt on the competence of them.

Edit: What vehicle?

**67hardtop** · 13th April 2018, 09:03 PM

Does it have ABS?

**justinc** · 13th April 2018, 09:14 PM

I would also check that they have put the clevis pin in the correct hole in the pedal... there are 2 to choose from in a d1. And there is also a possibility that they have got the booster pin to completely miss the master cylinder plunger....😣

**chillman** · 15th April 2018, 02:37 AM

Originally Posted by 67hardtop

Does it have ABS?

No ABS

**chillman** · 15th April 2018, 02:38 AM

Originally Posted by justinc

I would also check that they have put the clevis pin in the correct hole in the pedal... there are 2 to choose from in a d1. And there is also a possibility that they have got the booster pin to completely miss the master cylinder plunger....

New master cylinder + booster = worse brakes?

Thanks sounds promising. I’ll give that a shot.

**bee utey** · 15th April 2018, 08:27 AM

I'd be looking for a faulty (Britpart?) master cylinder being the cause of your problems.

**chillman** · 12th May 2018, 01:31 PM

I've flushed the fluid, I doubt it's air in the lines. The pedal is hard when you pump it without the motor running and as soon as I start it the pedal sinks to the floor like vacuum booster is working too well.

I looked up my eBay purchase and it doesn't say BritPart.

I'm stumped. Any suggestions for a good mobile mechanic near Coburg in Vic?

**chillman** · 26th June 2018, 02:54 PM

Originally Posted by bee utey

I'd be looking for a faulty (Britpart?) master cylinder being the cause of your problems.

Well the Midas franchise that did the work has gone bust and I can't say i'm surprised.

I've taken the car elsewhere and they think the master cylinder is faulty! You called it Bee Utey

**sierrafery** · 27th June 2018, 08:11 AM

Happened to me too on the D2... cheap unbranded one from ebay(so called "OEM quality") was bad from new, struggled two days with bleeding to figure it out... i bit the bullet then and bought a TRW which is still going strong after around 90K km. Classic case of "you get what you pay for"

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New master cylinder + booster = worse brakes?

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