Donald Markham wrote:
>
> I have a problem that I hope you can help me solve or at least point me in
> the right direction, I have just replaced the master cylinder, both front
> calipers and both rear wheel cylinders with NEW not rebuilt parts due to
> what I think was the DPO using DOT 3 brake fluid instead of DOT 4.
<<<snip>>>
There are at least two different kinds of DOT 4 Brake fluids. Castrol GTLMA
meets or exceeds DOT 3/4 specifications. It is composed of Alkyl Polyglycol
Ether Esters.
I have a bottle of MAG1 DOT4 fluid which says it can be used "for all Disc and
Drum brakes systems in which a DOT 4 or DOT 3 fluid is recommended." It is
composed of Polyalkylene Glycol Ethers. Unless some chemist out there tells me
these two compounds are the same, then these fluids a different.
ABout five years ago, I wrote Castrol inquiring about using GTLMA in the twin
cam's four wheel Dunlop disk brakes. Their response was that it was designed
for use in all Girling/Lockheed/Dunlop systems.
<<<snip>>>
>Is it possible that
> the braided hoses are bad as well?
<<<snip>>>
Not likely. The braided lines keep the hoses from swelling under pressure and
therefore give a firmer pedal. If the hoses were bad you would most likly see
dampness around the joints/unions or the brakes wouldn't completely release.
The low pedal or pedal play can often be fixed by adjusting the pushrod to the
master cylinder. Also check the link pin used on the push rod and the hinge pin
on the brake pedal. Any looseness here will cause excessive pedal play.
According to my references, the 72MG B doesn't have a brake booster. Couldn't
your problem be you're comparing Apples to Oranges? By that, I mean you're
familiar with a car with boosted brakes and the MGB with a unboosted system
requires more pedal effort. IMHO many American built cars are over boosted.
For me that decreases the pedal feel and makes it harder to modulate the pedal
to control brake lock up. All a brake booster does is lower the pedal effort
required to get a given retardation. It doesn't increase the brake's system
effectiveness. Vacuum boosters are placed on vehicles when the pedal effort
gets high enough that it becomes difficult to lock up the brakes.
ONe other possible problem is using racing type brake shoes or pads. Sometimes
these competition type pads raise the pedal effort needed. This is a trade off
for "harder" linings which resist fade better.
Blake
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