Weak Brakes

[Austin Healer]

The early series 5 Alpines had self adjusting rear brakes but it didn't take long for them to figure out they were a pain so the self adjusters were dropped. I've been around Rootes cars since the 60's and in all of those years I have not heard a Tiger owner say anything about the use of self adjusting brakes. Were there any Tigers built that used the self adjusters? The wife has an Alpine that retains the self adjusting rear brakes instead of using early Alpine wheel cylinders and it has the 700 master and no booster. The brakes are fine for the use that it gets. My green car does have the early wheel cylinders as well as the 700 master and no booster.

No, no Tiger had the self adjusters... The last Tiger I took apart had .750 rear wheel cylinders. The TR4A used the same design, but .70 rear wheel cylinders

 

[michael-king]

The article about adjusting the pressure sounds interesting. Where can I find it?

https://www.catmbr.org/cat-forum/threads/brake-pedal-ratios.7959/#post-48141

"With standard Sunbeam peddles (4:1), I like a soft peddle and use a 3/4" master.

Some like a firmer peddle and use a bigger master size.
a 7/8" master size, with no booster, makes for a VERY Firm peddle.

With bigger diameter Brake rotors, the peddle pressure should be less, the same braking as a smaller Dia rotor.

Changing JUST the peddle ratio up, 4:1 to 6;1 will reduce the peddle pressure.


BTW, the Tom H MODTIGER 6:1 peddle moves the peddle down, lower than the Clutch peddle.

 

[michael-king]

No, no Tiger had the self adjusters... The last Tiger I took apart had .750 rear wheel cylinders. The TR4A used the same design, but .70 rear wheel cylinders

I was suggesting Marty check what he has on the rear. Perhaps someone could have mixed some cross series parts and hence things may not be working right

I was trying to find a clear photo of them for a quick ID check... It's a long shot...but stuff happens to the cars over 60 years... My Alpine had earlier Lockheed drums off another rootes vehicle when I got it

 

[65beam]

No, no Tiger had the self adjusters... The last Tiger I took apart had .750 rear wheel cylinders. The TR4A used the same design, but .70 rear wheel cylinders

If you ever had to deal with the self adjustors you would understand why they were not a wanted feature. Rootes did have 250 conversions built using the series 2 Alpine and the cars had the Clayton Dewandre booster. You seem to have a good knowledge of other British marques. Was this C/W booster used on any other regular production

cars?

 

[KettleCarver]

I was suggesting Marty check what he has on the rear. Perhaps someone could have mixed some cross series parts and hence things may not be working right

I was trying to find a clear photo of them for a quick ID check... It's a long shot...but stuff happens to the cars over 60 years... My Alpine had earlier Lockheed drums off another rootes vehicle when I got it

That's not a bad thought. I have seen other Alpine parts on this car. The previous owner made some, shall we say, "interesting" choices on parts that they used. However, I don't know enough about Sunbeam brakes yet to know the difference. I could provide a picture of what I have, if that would help identify them.

 

[65beam]

I was suggesting Marty check what he has on the rear. Perhaps someone could have mixed some cross series parts and hence things may not be working right

I was trying to find a clear photo of them for a quick ID check... It's a long shot...but stuff happens to the cars over 60 years... My Alpine had earlier Lockheed drums off another rootes vehicle when I got it

The manual adjustment rear wheel cylinders for series 3, 4 and 5 Alpines are the same cylinder that was used on all series of Tigers. I stock new cylinders for all series of Alpines including the ones for self adjusters. I also stock new 700 brake masters. When I get back to the house this afternoon I should be able to take photos showing the cylinders side by side.

 

[KettleCarver]

Here are pictures of the rear brakes on my car. There is also a proportioning valve that I had not attempted to adjust yet.

 

[65beam]

https://www.catmbr.org/cat-forum/threads/brake-pedal-ratios.7959/#post-48141

"

Changing JUST the peddle ratio up, 4:1 to 6;1 will reduce the peddle pressure.


BTW, the Tom H MODTIGER 6:1 peddle moves the peddle down, lower than the Clutch peddle.

How much does the peddle ratio change when the brake pedal is moved down by using the second opening provided in the brake pedal arm? I have the brake pedal on all of my cars set to be lower than the clutch pedal.

 

[IvaTiger]

Just curious, thoughts of changing from the original braking system and getting into a wreck , what the insurance company feels about payout especially if serious damage is done to both the car and people or property?

 

[KettleCarver]

Sorry typing while walking... "Self adjusting drums" these were introduced on the SV alpine but then switched back... If someone had switched parts around you could have those and they are notorious for not working properly... But as stated earlier..front does most of the stopping.

Switch to the earlier MC will help with pedal feel and might get you to be able to get more stopping power earlier...

Quick question .. can you lock the brakes up when you hit them hard?

I got a chance to drive the car again today. And to answer your question, I cannot get the brakes to lock up, no matter how hard I stand on the brake pedal. I am not saying that the brakes don't stop the car. They do, .... eventually. Just not in a very confidence inspiring way. Every time I drive it, I pray no one pulls out directly in front of me.

 

[michael-king]

How much does the peddle ratio change when the brake pedal is moved down by using the second opening provided in the brake pedal arm? I have the brake pedal on all of my cars set to be lower than the clutch pedal.

Why don't you do a little research and maths Robert and let us know , you have a few cars there for reference.

 

[michael-king]

I got a chance to drive the car again today. And to answer your question, I cannot get the brakes to lock up, no matter how hard I stand on the brake pedal. I am not saying that the brakes don't stop the car. They do, .... eventually. Just not in a very confidence inspiring way. Every time I drive it, I pray no one pulls out directly in front of me.

Ok, you have an issue somewhere in your system as even a stock setup will be able to lock the brakes up.

The proportioning valve you have is very odd and not something that was part of the original system and definately not needed....

I'm wondering if that has been adjusted to give you more rear brake bias which would certainly reduce the effectiveness... It might also be fault and just causing a loss of effective pressure.

I'd dstrat by removing that from the system and see what happens.

 

[Theorangetiger]

How much does the peddle ratio change when the brake pedal is moved down by using the second opening provided in the brake pedal arm? I have the brake pedal on all of my cars set to be lower than the clutch pedal.

Essentially zero. The two holes on the pedals are equidistant from the fulcrum. They just give the pedal a different position fore or aft.

 

[65beam]

T

Essentially zero. The two holes on the pedals are equidistant from the fulcrum. They just give the pedal a different position fore or aft.

That's what I've always thought. I moved the brake pedal down in the 60's the first time I had to rebuild the master. I have never noticed a difference in the feel of the brakes.

 

[KettleCarver]

Ok, you have an issue somewhere in your system as even a stock setup will be able to lock the brakes up.

The proportioning valve you have is very odd and not something that was part of the original system and definately not needed....

I'm wondering if that has been adjusted to give you more rear brake bias which would certainly reduce the effectiveness... It might also be fault and just causing a loss of effective pressure.

I'd dstrat by removing that from the system and see what happens.

My local Tiger buddy gave me a set of semi-metallic brake pads to try. They did seem to increase the braking power a little bit, but still not enough to be able to lock up the brakes. I also tinkered with that bias valve. I did not have the parts on hand to remove it. It did seem to improve the firmness of the pedal a little bit too.

I also re-bled the system in accordance with the factory manual. It recommended adjusting the rear brakes till they lock before bleading. I was not aware of that.

My next step will be to remove that valve to see what happens. Unfortunately, I am running out of driving season here in Wisconsin. They use salt on the roads, so once it snows, I won't drive the car again till spring.