1972 Granada Mk1 coupe build - Still going... 14-10-2024

[eurogranada]

Jun 10, 2016 11:14:41 GMT minininjarob said:

Can I just say I keep coming back to this as I want to see it resolved! I can't offer any advice but I am heartened that so many people are trying their best to help eurogranada with some real in depth knowledge and experience. All good natured and respectful too.

This is what is so great about the internet forums, this one in particular.

First off, thanks for checking in every now and again on my continuous build... That in itself is appreciated!

I agree wholeheartedly with you. It's a great community for sure and I too was pleasantly surprised that people were even going back through the thread to help diagnose. Sure a lot has been covered over and over again, but it just goes to show people are trying to help with their two cents. Also someone offering physical help is a great thing.

I owe RR a lot. I have a place to work on the car because of it, I got a (possible) solution for my rev counter issue and now I also had some help on this brake issue.

So yeah RR is great!

[eurogranada]

Well, another weekend is mostly gone so let's update you all. Some of you will be eager to hear how we got on with the brakes.

So let's just start there. Thank you SamJ for taking some time out of you schedule to come around and help me diagnose the brakes!

With that said I think I'll try and keep it short.

Some things were checked:
- the pedal though changed over from manual to automatic is indeed the same as far as all mounting holes are concerned.
- the pedal return spring is now fitted for extra assurance and to prevent the MC innards from being the only thing pushing the pedal back to top position
- the pedal also has the required little amount of free play
- the one way valve is eliminated as suspect (both the Original and the Scorpio one were compared)

I had waited applying the brakes untill Sam could feel them for himself. From there we took the car for a little roll up and down the drive, both booster assisted and unassisted.

Sam's conclusion (correct me if I'm wrong or not telling it right) is that the brakes seem to work. The pedal feels pretty good with the engine off and it responds the same every time it is pushed. It does not sink when depressed for longer. The pedal does not pump up and therefore Sam is pretty sure there is no air in the system.

When driven, both with or without assist, the car stops. Without assist takes more effort of course, but with this MC it is stopping. With the assist the car stops every time. From speeds up to 20mph I guess... As Alignment is an issue I didn't go much faster.

Do the brakes feel confidence inspiring, yes and no. Yes as the car stops no as the pedal is pretty far down there. On the other hand, the pedal does not seem to reach maximum end of travel as suggested as it is a little bouncy at the bottom and also still above floor level.

Sam and I keep coming back to the assist... The assist is just very powerful. The booster keeps vacuum well as even after engine off, when the one way valve is released air is rushing in.

So what we doubt and could use input on: could the booster be defective? I mean it holds vacuum well, but should it be like this? How would a defective booster behave. We'd expect little to no assist would be the result, not over-assisting. Could the cosworth engine simply have a lot more powerfull vacuum then the Original 2.6 v6 engine? Rendering this booster overeffective? The Scorpio it comes from uses a booster about half the size. Can the amount of vacuum being pulled be regulated easily to lower it some?

One other observation: applying the brakes has a pretty substantial effect on the engine. When repeatedly applied the engine seems to suffer from it. Now I feel it is not running right at the moment. I would really like to check fuel pressure (no tools for that), verify that the swirl pot is working right, sparkplugs, that I have 6 Sparks, 6 injectors firing (what's the best way to do that) and compression. But that also takes time from doing the latest build stuff. And the engine running rough may possibly be from me having made a mistake in the wiring of the rev counter or speedo. Engine gives no codes by the way.

So I think those are the questions.

I do know for a fact that I've seen cosworth BOB engines in Granada's before with the same booster and MC (although at least one of those cars also had a valveblock in the lines near the inner wing. But as Sam pointed out, I don't know how the brakes in those car's felt. Mayb ethey felt just like mine.

So maybe I just need to accept and get used to the brakes as they are. But I was hesitant to think the could be OK.

Following Sam's advice, I'll now focus on the other stuff I want to get done so the car can go to alignment and MOT. Then I should just offer it up for testing, that should tell us what is going on. If the numbers are ok, then I know I just need to accept the working of the pedal as is.

Well that is the brake story.

The rest of the day was spent wiring up audio components and drilling mounting holes etc. No more subwoofers flying around the boot, lol.

Short term goal: finish up the audio.
Short + term goal: fix dash and finish wiring permanently

After that I may just have to offer it up for alignment and MOT.

Thanks for reading my gibberish...

[gess]

A new pair of eyes (and feet) can often be helpful. One importent thing to remember is that your daily drive is a fairly new car with good brakes. The fact that the Granada pedal feels different may simply be just that. It is different, old fashioned and less refined. If the pedal doesn't drop to the floor when applying a heavy pressure to the pedal, you don't have any leakages at least. I do believe that the brakes on my Granada needs the pedal to be pushed further than on my Hyundai to work. But that is just a difference between the crs, old and new.
On my Granadas, I have noticed that the enginges loose revs if the pedal is depresses several times in a quick repeated pattern. I wonder if I was able to get the revs down to near stall by just applying the brakes repeatedly. It messes with the manifold pressure, so I wouldn't worry too much unless you stall the car when driving and breaking.
Will be interresting to see the MOT result,especially the brake test :-)

[SamJ]

I had a look through the APK manual, there is nothing in there regarding minimum brake pedal force. The brakes need to be able to decelerate the vehicle at a minimum of 5.2 m/s2, with a brake pedal force less than 500 Newtons, and the travel of the pedal should not be limited by anything other than the hydraulics. On those terms, I think you will be fine.

[therealpinto]

I think you have done a good job on sorting these issues.

It is possible that the 24v will pull a slightly stronger vacuum, and what you're feeling may be a case of over-assist. It might be possible to find a vacuum regulator to lower the vacuum a bit, not sure about that. But you don't want to induce a vacuum leak either.

The long-term solution is probably a smaller brake servo (or find one with less assist, but data is often hard to find).

I would not worry more about this now, until you have the chance to drive the car and get used to the feeling. TBH, my strongest memory of driving a 3.0 Ghia MkI Granada, was the strong servo assist of brakes and steering...

Regards

Gustaf

[The Doctor]

Did you improve the brakes this saturday?
Because being used to modern brakes is one thing, but Dennis drove your car the week before IIRC, and he told me that he thought your brakes where curse word, just not giving any trust under braking.

Not that i want to talk you down or anything like that, i just don't want to see it wrapped around a tree, because something is/was wrong with the brake system!

[eurogranada]

Jun 13, 2016 13:34:58 GMT The Doctor said:

Did you improve the brakes this saturday?
Because being used to modern brakes is one thing, but Dennis drove your car the week before IIRC, and he told me that he thought your brakes where curse word, just not giving any trust under braking.

Not that i want to talk you down or anything like that, i just don't want to see it wrapped around a tree, because something is/was wrong with the brake system!

A little was done... A final bleed, tightening up of the lines that had been undone to change the MC, also the return spring fitted and the original pedal double checked for correctness. But generally just small stuff.

I don't want to see it wrapped around a tree either! And I have to say, I'm not yet fully convinced everything is right either. But that said, we tested the system to a reasonable extent and don't have a better answer as yet.

We verified the behaviour of the pedal, proving no air going by the fact that the brakes could not be pumped up. We tested the pedal both with and without assist and without it, it feels pretty normal. We also drove the car more than Dennis did. And everytime the car stops. It can even stop quite firmly. But the fact that alignment is not set is clouding judgement a bit, suspension components aren't locked in so they "give" too much. You can see this under braking. I guess with that all correctly set, that extra movement will be lost and actual braking efficiency improved. Although that does nothing for the pedal position.

The general feeling both me and SamJ had, was that possibly the boost was just too much, but the brakes themselves seem ok.

Again, I wouldn't have raised this issue and even tried three MC's at considerable expense if I was immediately confident about the brakes. The confidence is still low, but Sam may be right, maybe this is just how the brakes are. As they do work. And his thinking was that if we can't find another obvious cause in this relatively simple system, then maybe we should conclude it is ok, an MOT test would prove this either right or wrong (and usually also show this in actual numbers helping diagnose the situaion).

So I personally am not yet closing the book on this subject, but I do see sense in Sam's reasoning to get the last things MOT ready and just go for it. Worst case scenario it fails on its brakes.

Also the car will be transported to the MOT station, mostly due to lack of alignement, so I'm not really risking driving the car yet. If the MOT station gives it the all clear, then who am I to say it's not right. In that case it would just be different from what I'm used to. Still, until proven ok, I have my doubts. And I think Sam is also not 100% sure, but we've found no obvious things wrong. SamJ will chime in if I've misrepresented his thoughts I'm sure.

[stealthstylz]

Lots of travel before the brakes start to bite properly means the master cylinder is too small.

[eurogranada]

Jun 13, 2016 14:37:12 GMT stealthstylz said:

Lots of travel before the brakes start to bite properly means the master cylinder is too small.

It's the biggest one ford offers for the Granada, 23.8mm innards...

[therealpinto]

One option is of course to find a bolt-on larger cylinder (25,4 mm is usually the next step) to see if things change but it shouldn't be necessary with all "standard parts".

Gustaf

[westbay]

25.4 mm master cylinder :-

Ford Transit
Ford Galaxy 1.9TDi

[eurogranada]

Jun 13, 2016 15:01:55 GMT westbay said:

25.4 mm master cylinder :-

Ford Transit
Ford Galaxy 1.9TDi

Yeah but another expense, and will they fit the booster etc... Also as one said, it should simply be able to work....its all original granada stuff.

[Paul Y]

Probably already checked this but might be worth double checking the pedal ratio?

Not wanting to educate your mothers mother in the fine art of applying vacuum to an egg but I found this useful a few weeks ago.

www.mpbrakes.com/techtalk/how-to-series/correctly-calculating-pedal-ratio

Applaud your approach on not driving it until you are happy with the brakes.

P.

[scimjim]

Jun 12, 2016 14:20:36 GMT eurogranada said:

One other observation: applying the brakes has a pretty substantial effect on the engine. When repeatedly applied the engine seems to suffer from it.

Despite all of your other checks, this symptom suggests an air leak in the servo or servo pipe. Once the engine is running well, if it still drops the revs when you push the pedal, I'd do a full check for leaks?

[Siert]

"Too much" vacuum to the booster with a different engine sounds like a reasonable explanation to me. I tend to agree with your friend that you should probably focus on other issues first, but I guess you could just attach a cheap vacuum gauge to the brake booster hose and see what kind of vacuum you get now and how much that differs from standard?

If you can't get a range for the value on a standard Granada anywhere you may be able to ask some friends with Fords that have similar engines to your original Granada engine?

I'm no expert on air flow, but I guess reducing the vacuum to a desired range should be quite easy?

[eurogranada]

Jun 13, 2016 16:23:55 GMT Paul Y said:

Probably already checked this but might be worth double checking the pedal ratio?

Not wanting to educate your mothers mother in the fine art of applying vacuum to an egg but I found this useful a few weeks ago.

www.mpbrakes.com/techtalk/how-to-series/correctly-calculating-pedal-ratio

Applaud your approach on not driving it until you are happy with the brakes.

P.

I read the link. But This should not be the cause.

I use an original granada automatic brake pedal (although the car was originally a manual car), in the original pedal box on the original pedal shaft, attached to the original booster (same for all larger V6 engined models) with the original pushrod and ending in an original (albeit later model Granada) MC.

I actually verified the manual pedal versus the automatic pedal this weekend again, to be sure I hadn't overlooked anything when converting the pedal box.

So I'm pretty sure this is not it.

But I'm for now taking the approach to get the car MOT ready and aligned so at MOT time the brakes will be proven either ok, or rubbish officially. And if they are rubbish officially, I think I'll just drop the car somewhere and tell them to fix it.

[eurogranada]

Jun 13, 2016 19:45:52 GMT Siert said:

"Too much" vacuum to the booster with a different engine sounds like a reasonable explanation to me. I tend to agree with your friend that you should probably focus on other issues first, but I guess you could just attach a cheap vacuum gauge to the brake booster hose and see what kind of vacuum you get now and how much that differs from standard?

If you can't get a range for the value on a standard Granada anywhere you may be able to ask some friends with Fords that have similar engines to your original Granada engine?

I'm no expert on air flow, but I guess reducing the vacuum to a desired range should be quite easy?

I've asked around for some brake values from friends. Maybe this will bring something more to light.

Personally I wouldn't yet know how to decrease vacuum from an engine port.

[Phil H]

On my car (1974 Scimitar) I've fitted a more modern engine of the same sort of age as your 24V (GM X30XE), so it's mixing 1970's and 1990's technology and don't find any real difference in braking effort over an original car but older brakes are "longer" in the pedal than modern ones. Any increase in vacuum should be negligible in my opinion.

Master cylinder size should only be affected if you've changed the wheel end (calipers/cylinders) - I haven't had the opportunity to go back through your thread to see if that's the case though?

[Paul Y]

Jun 14, 2016 7:18:51 GMT eurogranada said:

Jun 13, 2016 16:23:55 GMT Paul Y said:

Probably already checked this but might be worth double checking the pedal ratio?

Not wanting to educate your mothers mother in the fine art of applying vacuum to an egg but I found this useful a few weeks ago.

www.mpbrakes.com/techtalk/how-to-series/correctly-calculating-pedal-ratio

Applaud your approach on not driving it until you are happy with the brakes.

P.

I read the link. But This should not be the cause.

I use an original granada automatic brake pedal (although the car was originally a manual car), in the original pedal box on the original pedal shaft, attached to the original booster (same for all larger V6 engined models) with the original pushrod and ending in an original (albeit later model Granada) MC.

I actually verified the manual pedal versus the automatic pedal this weekend again, to be sure I hadn't overlooked anything when converting the pedal box.

So I'm pretty sure this is not it.

But I'm for now taking the approach to get the car MOT ready and aligned so at MOT time the brakes will be proven either ok, or rubbish officially. And if they are rubbish officially, I think I'll just drop the car somewhere and tell them to fix it.

For 10 minutes with a tape measure might it not be worth a check to ensure the ratio is right?

Knock the simple stuff off first before getting into vacuum etc.

P.

[Phil H]

When you say a later model Granada master cylinder, how much later?

The whole setup (master cylinder, servo and pedal box) will be matched to give a certain amount of fluid movement to the wheels for a certain movement at the actual pedal end.

For example - if it's all arranged to make 10cc of fluid (no idea if that is right or not - random figure) for a 50% pedal depression by your foot, that will translate to a (again example figure) 15mm movement of the piston. As its a direct acting servo, that will be 15mm of the pushrod, hence 15mm at that part of the pedal which by the leverage ratio will be (say) 100mm at the pedal rubber - your foot.

If you are trying to move more fluid (due to larger Pistons in the calipers), then the MC can't do this without more stroke - in which case normally you would try and go up a size to match the ratio. This then keeps the servo and pedal bit happy as it does the same linear movement (travel) to move the caliper pistons out the same amount.

If, however, Ford at some point changed the setup to make it less servo and master cylinder travel then either the caliper pistons will get smaller or the master cylinder bore gets bigger to adjust the ratio to match the new pedal lever ratio.

In short - pedal/servo/master cylinder/calipers need to match original. If anything is different from original, then what's the difference? If it all matches, then it might simply have a longer pedal than one is used to - either that, or the rears have too much clearance (adjusters not working correctly?) and the "slack" is taken up by them first resulting in a long pedal?

Apologies if this is already known - just thinking out loud.