brake fluid... DOT 3 or 4?

[norton 82]

i checked the number on the bottles and there was none on the DOT 4 and the correct number as per Haynes on the DOT 3.   i've a bit of a nagging doubt though..... is DOT 3 right? the Interweb tells me " Ford recommend DOT 4 " but that's for modern cars I assume.

 

I've no idea whats actually in the car of course.

Edited March 11 by norton

[Deano66 205]

Hi Norton,you've probably got DOT3 in your car,the only difference between DOT3 & 4 is that DOT4 has a higher boiling point.You can add DOT4 to DOT3,but not DOT3 to 4.

[norton 82]

2 minutes ago, Deano66 said:

Hi Norton,you've probably got DOT3 in your car,the only difference between DOT3 & 4 is that DOT4 has a higher boiling point.You can add DOT4 to DOT3,but not DOT3 to 4.

thanks for that. i don't think the fluid has been looked at for years, so I was assuming it was DOT 3 . The reservoir was nearly empty, first time on the road this weekend, so just as well i checked. I have a new DOT 4 botttle, so good to know I can use that, and use DOT 4 going forward. When i get a round tuit , i'll change the fluid completely. 

[sheffieldcortinacentre 532]

Yep you can put higher number in without probs, just don't mix silicone fluid with mineral.

[Tigdlo 26]

If the fluid has been in there a long time, it’s probably mainly H2O!

I would suggest changing it asap.

[norton 82]

15 hours ago, Tigdlo said:

If the fluid has been in there a long time, it’s probably mainly H2O!

I would suggest changing it asap.

it was so empty, it's now mainly brake fluid. The next bleeding will shift a lot of what's still there, never seen a car so empty, I hope the previous owner didn't skimp anything else!