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Discussion Starter · #1 ·
I have just purchased a standard (15" wheels) 2002 built TF and am surprised by how much pedal force is required to get a reasonably quick stop. I have been told that this is "normal" for the standard brakes "which is why so many people fit the larger discs and AP calipers", which of course necessitates 16" wheels, a new set of tyres etc. As the Conti tyres on my MGF are in good nick and I suspect the 16" lower-profile tyres will make the ride firmer, I am reluctant to go down that route. Does anyone offer high-friction pads? More to the point, if they exist, do they work?? Anyone out there have experience of this problem and have any ideas, or do I need to start weight training to develop stronger leg muscles?
 

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Never found a problem with the stand brake size even when using euro car parts disc and pads :p and I regularly swap between my 160 which has the 4 pots and my 75th which has standard. Have you checked/can you check when the brake fluid was last changed? it maybe worth bleeding through new fluid on all brakes as its recommended to change every 30k miles or two years
 

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As said the fluid should be first on the list if it more than two years old.

The rear brake callipers may not be working very well meaning that more of braking is being done by the front brakes.

But lastly look how much the brake servo moves when you press the brake pedal, that is likely to be where most of the brake inactivity stems from. There are a number of bolt on brackets that will stop that movement and makes a massive difference. The only caveat is that with most of them you will need the later heater intake box.
 

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Dont condemn the existing brakes until yu know they are working as they should be. Take all four wheels off and check, clean and lubricate the calipers and pistons, in particular the slider pins for dirt or seizure.

If you want to try a different pad, try a reputable brand, such as Mintex.

Good luck.
 

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Discussion Starter · #5 ·
Thanks for all the comments so far. Everything said is very helpful and makes sense. I have a book of receipts going back to when the car was purchased. The last receipt SPECIFICALLY mentioning brake fluid was March 2017, so some bleeding and a can of DOT5 brake fluid sounds like a good investment. Having said that, the fluid visible in the reservoir looks clean, as does everything else visible.
"Bennet" my MGF, will be going through the braking test part of an MOT later today at my trusted local garage (Honiton Garage, they have a resident ex-Rover MGF expert) to check if I am being stupid/automotive hypochondriac, so someone more informed and experienced than me, with hard data will be able to pass judgement.
P.S. my previous Toy, built-myself 32 years ago, was a Griffon110 kit car I named "Gordon" geddit??
 

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classic_mg
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You would be surprised how much the bulkhead flexes around the brake servo. It's worth thinking about fitting a reinforcement braked from Mike Satur or others.

 

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I find the brakes on my F excellent, no excessive pedal force needed. I did replace the original, decades old rubber brake hoses with braided hoses, which did improve braking performance.
 

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'06 MG ZR +120 (HQM) '04 MG ZR 105 (IAB)
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...... last receipt SPECIFICALLY mentioning brake fluid was March 2017, so some bleeding and a can of DOT5 brake fluid sounds like a good investment.
errrr......DOT 4 ;)

If it was last changed 4 years ago, I would think it is probably well ready for another complete change tbh (recommended to change every two years, although with modern brake fluid testers available, that can liokely be extended in most cases.

Like the others, I would go for a check that the slider pins are working freely, and that the pistons have not become trapped by the rubber boots (rust often eats its way round into the groove on the barrel of the caliper housing where the boot fits and results in the rubber being 'pushed out' against the side of the piston and acts like a brake on the movement of the piston). Trapped air will also impede brake force as air takes more compressing than brake fluid.

Another thing which sometimes occurs is that the rubber hoses to the calipers beome weakened, and the pressure of the fluid when you press the pedal expands the hose rather than pushing the caliper piston out. On occasions, the rubber inside can degrade and swell up, which then impedes fluid flow to the caliper. New hoses (or better still, braided hoses, should solve this if it is a problem).

The other thing to consider is whether the master cylinder and servo are operating correctly - the master cylinder may be loosing presure back past a worn seal - seal kits can be got, or a complete replacement master cylinder if needed.

As already mentioned by others, the brace for the servo mounting can make a big difference regardless of anything else, and is a long standing, well known and trusted modification.
 

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Discussion Starter · #10 ·
All advice about braided hoses servo mounting brace and fluid changes noted. The brake test revealed an overall brake efficiency of 66%, which is well above the MOT minimum pass value of 50%, but I wonder what is a "normal" result for a system in good condition. The rear brakes ARE as some above suggested, underperforming relative to the front 64% versus 68%, and both of the nearside brakes are producing about 10% less force than the offside. Is this significant?

Hoses look to be in good condition, but could be original, as this car has only 22000 miles on the clock, and a complete set of MOTs and service bills support this fact. Perhaps rubber should not be expected to be at it's best after 18 years, so braided hoses will go on soon and a complete fluid change will be a side effect.
136659
 

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That is a very clean and non rusty looking vehicle :O a rare sight to see.....rear brakes are prone to seize so check the pistons are moving freely, the brake pipes look fine...I'd do a fluid change....amazon do a lire of dot4 for around £4.99 so it won't be expensive if you decide to go for braided if it still don't feel right to you...your other option is to find someone else who has an F/TF and ask them to drive yours and for you to drive theirs to see if the brakes feel different :p
 

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Discussion Starter · #12 ·
Yes, generally non rusty and thanks for the tip re DOT 4 fluid on Amazon. Would be happy to check-out and compare someone else's MGF esp. if they have fitted "Softride" suspension. (Wife is already complaining of harsh ride)

Any volunteers in Devon? Currently travelling between Honiton and Barnstaple quite often but yet to spot another MGF on the road. Mazda MX5's common as muck of course!
Examination of the underside while the while brake check was done at local garage DID show-up some rust. Seemiddle of right hand edge of the image below:
136660

I am intending to look more closely when I am back at home, while checking N/S brakes for sticking pins, any signs of brake hose degradation etc. I think I will do some rust removal and painting the offending area, as long as I can avoid getting paint solvent on rubber: not sure what rubber bits are near those rusty bits yet.

Any suggestions what to use?. Last time I did anything like this was 32 years ago and Waxoil or was it Waxoyl? was the answer to everything.
 

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I tend to treat rusty areas once wire brushed down with phosphoric acid, the same stuff as in coke and many over the counter rust treatment remedies as it will convert rust into a layer of ferric phosphate which can then be painted. There are all sorts of paints, etc, but I usually do a coat or two of of red oxide and then finish off with a couple of coats of black exterior gloss....not had any problem with one of my subframes I did over 5 years ago :)
 

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What is up with this site? posted a message early and it just posted it again...grr changed the double post to one of my subframe instead :)
136666
 

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I originally used POR15 to paint my subframes. It's a nasty polyurethane formulation that you can't get off your skin for a week if you spill it - and forget about cleaning brushes, they're toast after one use. On paper it sounded great but it needed two coats within a specific time interval and events got in my way so I was stuck with a single coat of it on my subframes but putting the second coat on at that stage would have meant (so I understood) it wouldn't have bonded without going over with some kind of acid etch primer or sanding the lot.
Anyway, I though better of the whole POR15 business and went for Hammerite Underseal with Waxoyl. Later on I used Dinitrol 4941 (?) spray on underseal which gives a nicer more even finish than application by brush.
I did find an area of POR15 peeling a couple of years later - not what I was expecting from something that is supposed to cling onto bare metal tenaciously. Anyway, my preference these days for under the car is a bitumen type softish underseal of some sort. Never seen it peel!
 

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Discussion Starter · #16 ·
Thanks for all the tips. As ever these forums are a goldmine of information. I am now getting used to the brakes and have learned that size 9 feet should be without the right-hand shoe. My toe was catching the underside of the trim below the steering wheel. This restricted free movement and part of shoe was pressing accelerator while braking. Clutch was released but screaming engine noise was a distraction.
Brakes seemed to have improved having appplied 0.99 hernias worth of pedal force with engine running. Did this wake up a sleeping servo, which has only done 300 miles in the previous 4 years?
Thanks again everyone for all the advice.
 

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rover_25
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You cant use dot 5, its silcone based, you need dot 5.1, give the brakes a good bleed and get some stainless hoses, if its still abit iffy, get some yellow stuff pads from ebc
 
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