TR2/3/3A TR3 Sticking Brakes - How come and what to do?

[TR3TomG]

Can anyone let me know why when I locked up my brakes the other day, they then (I think at least the left front) dragged?. Anyone have a recommendation on what to do about it? Should I just open the bleader a bit and let off a bit of pressure? Thanks

 

[Geo Hahn]

If yours is in fact only dragging on the LF then I would suspect some contamination/corrosion may be preventing the piston from withdrawing that tiny bit it must move when the brake is released.

Another possibility (albeit one I have never experienced) is that the brake hose can fail internally causing a sort of check-valve effect and holding pressure. I believe this can occur even if the hose appears fine on the outside (inside either swells shut or a little flap develops).

You can certainly crack open the bleeder, then test the brakes and see if the problem recurs.

If you find that the problem is not confined to just one wheel then other causes are possible including the restrictor valve and the master cylinder.

 

[TR3driver]

Another possibility (albeit one I have never experienced) is that the brake hose can fail internally causing a sort of check-valve effect and holding pressure. I believe this can occur even if the hose appears fine on the outside (inside either swells shut or a little flap develops).

Happened to me several years ago, although it was the rear brake hose. Looked OK on the outside, not new but noticeably weather checked or rotted. However it caused the rear brakes to drag enough to overheat in traffic. At one point they were literally smoking!

When I later cut the hose open, it appeared that the inner lining had torn somehow, and there was a little wad of material blocking the bore.

If cracking the bleed valve causes them to relax, then I'd first change the hoses, and then, if the problem persists, the residual pressure valve (on top of the 5-way union). (Actually, I just gutted my RPV years ago, because I didn't like the brakes dragging even lightly.)

 

[Brinkerhoff]

I also gutted the "residual pressure valve" to fix my dragging front brakes. I don't think its in the shop manual.

 

[lbcs_r_fun]

Can anyone let me know why when I locked up my brakes the other day, they then (I think at least the left front) dragged?. Anyone have a recommendation on what to do about it? Should I just open the bleader a bit and let off a bit of pressure? Thanks

<span style="font-weight: bold"><span style="text-decoration: underline">Details regarding residual pressure valve here:</span></span>

https://www.britishcarforum.com/bcforum/u...alve#Post428055

T

 

[TR3driver]

Here's a little more information