I have just bought a ā89 MK1 1.6 and in my opinion there doesnāt seem to be much power assistance in the brakes. Ā You have to press really hard and the pedal feels hard (it does not have that slightly spongy feel that power assist normally adds).Ā
Is this normal? Am I just too used to modern cars with loads of assist?
Iāve not yet taken the vacuum hose off to check thereās proper vacuum. The brakes work fine as such. They donāt seem to bind and the car stay dead straight during braking from any speed. But you really have to brake hard and you can just about lock the wheels up if you REALLY push it (No ABS).Ā
Some guidance from more experienced owners is very welcome.Ā
Try pressing the brake pedal with the car in neutral and the engine stopped (no inlet vacuum). Then without easing off the brake pedal, start the engine. The feel of the pedal should change; it should move down slightly. If not, the servo or pipework might be faulty.
Ah yes of course! thanks Paul, I will try that. Itās been such a long time since I drove an honest, analogue car. Been cocooned for too long in these modern hybrids.
We have 2 5ās, a 2002 Sport & my '93NAā¦which also is an Auto.
We have had them both for nearly 16 years , and have no issue through years of habit with eitherās āfirm applicationā of brakesā¦the Sport more so than mine.
However, Iām also insured to drive my sonās 2014 plate Fiesta, and suffice to say it takes a few miles to acclimatise to the fact if I use the same amount of braking forceā¦were it not for the seat belt my incisors would embed themselves in the steering wheelā¦the same with an elderly neighbourās newish Pug which they entrust me with to āloosen upā now and then as they do not use it much.Ā
However, youāve been given a possible check/solutionā¦soā¦good luck with that.Ā Ā Ā
While depressed, the pedal does go down a little bit when starting the engine > good sign
checked vacuum at the brake servo and get a steady reading of 47-48 cmHg > spot on
Tried braking with vacuum disconnected and then reconnected. There is definitely a big difference.
I can only conclude that this is a combination of me not being used to the car and a rather modest assist.
That said, until Iāve gone over the brakes and exercised the pistons at each wheel and replaced the brake fluid with new ditto, I will still not be entirely convinced. I did notice that the main cylinder is āsweatingā somewhat. There even appears to be a thin thin layer of fluid below the cylinder. Is this a common age related ailment? Iāve not seen any master cylinder gasket refurb kits. Buying a new was horrendously expensive.Ā
I will clean off everything so I can hopefully get a sense for the rate of seeping and where it comes from. I kept things dirty for the photos so I have a record of what it looked like.Ā
Hiya, looking at the last picture, the slight amount of fluid showing may just be spillage from when the resevoir has been topped up? As you said, clean it off and monitor the situation.
Sounds like you have checked everything and in all probability , like others have said , brake efficiency has evolved significantly over 30 years causing the noticeable difference vs your modern ādailyā . I certainly treat the pedal on my big 6 month old barge with a degree of ātendernessā compared to the Mk1.Ā One thing I did find that seemed to firm matters up on the Mazda (mineās only 28 ) was the fitment of Hel Braided flexi hoses . Worth a try if you are still in need of improved retardation so to speak !Ā
Before you go any further you need to make sure what you have is working properly as you have suggested.
Strip each brake in turn.
Replace any rear disc that is under 7mm thick and front disc that is under 16mm in thickness. This assumes that 1600 cc brakes are used.
I tend to replace disc pads with around 7mm thickness, others will say the disc pads will last longer.
Make sure that red rubber grease is used in the slider pins rubber socket interface, not copperslip and that any metal to metal sliding surfaces are lightly covered not too much with ceramic grease.
Over the years the operating mechanisms can go out of adjustment and the mellens.com workshop manuals give guidance on making brake pedal adjustments, testing the āBrake Boosterā and adjusting the ābrake boosterā master cylinder clearances.
In my experience once all this work is done the braking system will be quite impressive.
Another possibility is that the brake surfaces have become āglazedā, both discs and pads polished up to gloss and just skating over.Ā This can happen when a car is driven too gentlyā¦Ā
Years ago I bought a car with seemingly duff brakes despite a working servo (tested as above), and on the way home they only began to work properly after a major panic stop when the motorway ahead suddenly became a sea of red brake lights.Ā With that car (FE Victor Estate) I put the discs on the lathe and scrubbed off the glossy surfaces with an emery pad and also put new brake pads in.Ā After that it was superb.
With my NC more recently the rear discs became so rusted by a couple of weeks parked at Gatwick they did almost nothing, and a skim/clean up and new pads again made an enormous difference.Ā I hadnāt realised quite how much the NC rear brakes did until being able to compare how well the car sat with brakes working all round instead of pitching forward with only fronts effective.
Richard - you are right about glaze on the discs. The previous owner only did 300 km with the car in the last 12 months and about 1000 km over the past two years. So, yes, thatās nowhere near enough use. Particularly as it was kept outdoors (not good!). Even after the 60 mile journey to bring the car home and some additional āworkoutā - the glaze was obvious when I took off the wheels to inspectā¦
I have since, tried to remove the glaze and rust with a rotating wire brush (working from centre out) and bled the brakes. Cylinders are moving freely all around. The fluid needs changing.
I also had an mx5 specialist test the car and got the verdict - āitās fine.ā.
Well so, itās all good enough for now. It will be better once I decide to put new discs and pads on.
Unfortunately a wire brush isnāt really hard enough to remove the glaze, although a stainless steel bristled one will remove the surface rust. However, some disc pads have an abrasive coating, which is designed to ābustā the glaze on the disc and bed them in quickly. I think one type Iāve fitted in the past were made by APEC. It might be worth fitting new discs, though, best not to take chances with brakes.
Just a quick response offering an alternative view. I personally donāt like the excessive servo assistance on my other cars (BMW Z4 & BMW Mini) and I do like the extra āfeelā I get from having to exert some of my own muscle. Either way, hope you get to where you are happy with your brakes; they are kinda important!
You are absolutely right. If I had a lathe I could remove a few 100th of a mm. Inevitably, new discs and pads will certainly be put on. The current discs have actually not done many miles and they are quite good as is. Iām satisfies, the pads sweep the whole surface and are effective. Iāve also flushed and replaced the fluid.
There is a problem with removing anything other than light rust from discs that the brake action itself should be capable of clearing.
The material/tools required will remove sufficient removal as to take a lot of brake action, particularly on the rears to get them right again and likely by that stage the original problem is back.
I have used aluminium oxide paper and thinking about it a well used flapper disc on a grinder would be a lot easier and quicker but probably require new pads with the top abrasive layer to bed in sufficiently quickly to be useful.
Looking at the picture, it is not easy to assess but on the face of it probably worth removing the disc and having a quick try to remove the glaze. As I am sure you are aware that glaze will be on both sides of the disc.Ā Ā Ā
Brake discs and pads are so cheap. I seem to remember replacing all four corners on the Eunos 4 or so years ago with quality parts from various suppliers for around Ā£50 all in delivered.Ā Ā Ā
Since weāre all here to learn from our joint experiences I thought Iād post a quick update on this thread.Ā
In short, the āproblemā with my brakes were, as many of you suspected, simply a case of glazing due to lack of use. In the two months that Iāve owned the car Iāve covered more distance than the previous owner did over the last two years! The issue becomes more apparent when you compare photos of one of the brake discs before and after.
Ā
Shortly after I bought the car - you can see plenty of dark areas of rust that has been āsmushedā down and polished by the pads to a lovely shineā¦
And after about 1500km of āmixedā driving - much of the rust has now worn off and fresh, grippy steel exposedā¦
The brakes now feel as I would expect from a car this age - perfectly adequate. The change has been very gradual but I can definitely tell the difference. Iām no longer having to retrain when moving between the Mazda and my modern daily driver.Ā
There are still some dark spots on the discs but they are small and will over time disappear. Iām just keeping an eye on disc and pad thickness but the discs clearly have not covered many miles since they were installed. Plenty of smile-miles to go!
