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Servo or no servo
Posted: Wed Jul 05, 2023 9:21 pm
by Molly123
I recently bought another minor which had front disc brakes, but no servo.
I found braking without the servo no better than with the original drum brakes. I decided to have a servo fitted.
Now I find when braking the brakes snap on suddenly with no gradual slowing.
I’d be interested in the views of other members who have a servo fitted.
Many thanks
Seth
Re: Servo or no servo
Posted: Wed Jul 05, 2023 9:35 pm
by jagnut66
Hi,
I like to fit disc brakes but I haven't added a servo into the set up for a while now. without a servo the brake pedal feel is harder / it takes a little more effort to apply the brakes but not (IMO) excessively so.
For me disc brakes allow an emergency stop if needed and give better overall braking performance, plus they require less maintenance, namely you don't have to constantly check their adjustment.
For me a servo is just something else in the loop to go wrong.
Like I said just my opinion but now watch me get shot down for daring to say that!........
Best wishes,
Mike.
Re: Servo or no servo
Posted: Wed Jul 05, 2023 9:41 pm
by Molly123
Thanks Mike. I’m leaning towards having the servo removed.
Re: Servo or no servo
Posted: Wed Jul 05, 2023 11:04 pm
by ManyMinors
There is absolutely no need for a servo to be fitted on a Morris Minor.
Re: Servo or no servo
Posted: Thu Jul 06, 2023 6:15 am
by Molly123
Thanks MM
Seth
Re: Servo or no servo
Posted: Thu Jul 06, 2023 7:29 am
by oliver90owner
The servo will, if operating correctly, reduce the pedal pressure for the same operational action at the wheel. That the brakes are too fierce with minimum pedal operation may mean the servo is too big for the application or not completely matched to the application.
The simple alteration is to fit a harder grade of brake pad. Brake pads which are too soft will likely suffer from heavy wear - and early fade as they overheat, too. Harder pads should be able to take advantage of the full power provided by the servo.
Try your modern car without the engine running (and any vacuum source used up). Do this somewhere safe! Braking would be very seriously reduced!
Exactly the same as modern-day power steering. Light steering with and strong-arm steering without!
My experience of changing pads comes from Cortina/Escort modifications. My brother’s included Anglias, too
I would expect a change of master cylinder diameter would also change the braking sensitivity. Brake systems need to be matched, as to their components, not just thrown together. We also experienced the same problems when changing the clutches to diaphragm type. We actually put up with a very heavy clutch pedal, (in our youth) but, in retrospect, we should have changed the master/slave sizes to ease that problem. The coil spring clutches of the day were totally inadequate for the increased torque of the hotted-up engine mods we installed and the ensuing clutch slip soon over-heated the parts and wore out the drive plates.
Re: Servo or no servo
Posted: Thu Jul 06, 2023 7:57 am
by Molly123
Thanks Oliver for your input.
Seth
Re: Servo or no servo
Posted: Thu Jul 06, 2023 7:24 pm
by Bill_qaz
Sounds like wrong ratio servo giving over assistance. Mine came with Marina discs and servo and the braking is very progressive and still a harder to push pedal than my modern car.
Re: Servo or no servo
Posted: Thu Jul 06, 2023 9:28 pm
by simmitc
Ah, the times this has been discussed. Let's just say that there is a difference of opinion! That established, I have a Saloon with standard drums and two Travellers with Marina discs, both with servos. I can lock all four wheels on all the cars, but the discs require far less maintenance and pads are quicker to change than shoes. I much prefer the discs with a servo, they are progressive and do not snatch at all. I have never had a servo fail, but have changed plenty of wheel cylinders until I swapped to silicone fluid (another much debated topic). As has been mentioned above, the importqnt thing is that all components are properly matched - and also properly installed.