Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here


brake fluid reservoir - material

brake fluid reservoir - material

brake fluid reservoir - material

Hello colleagues,
I'm new on this forum and just need some help. I'm working for 3d printer producer and I have the case study to do:
I have to print brake fluid reservoir that is normally used in cars...
Do you have any idea what is the original material that such reservoires are made of? I do not know if every kind of filament will handle the chemical requirements that such reservoires have to pass. Maybe the brake fluid has some special chemical prosperities?

I'll be very glad for your help.

PS. If I added this topic to the wrong section of forum please forgive me.

RE: brake fluid reservoir - material

Someone more knowledgeable on the subject may be able to correct me if I am wrong, but I thought they were usually made of HDPE.

Andrew H.

RE: brake fluid reservoir - material

Printing with HDPE filament is... tricky. Did it once. Prefer never to do it again. The stuff shrinks intolerably, and getting it to stick to itself is a serious challenge.

Dan - Owner

RE: brake fluid reservoir - material

Polyethylene or polypropylene are about your only choices, at least for the DOT-3 and DOT-4 glycol ester brake fluids. Teflon would work, but not PVDF. And as Mac suggested, fused-deposition printing with any of those is tricky. Making (or suggesting that others make) a possibly leaky brake fluid reservoir, and its resulting life safety issues makes the idea a non-starter, IMO.

RE: brake fluid reservoir - material

Gross overkill but you could do DMLS in 316 stainless.


The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

RE: brake fluid reservoir - material

Thank you for the answers, safety requirements are not a problem as it should be only as as a sample and not being in normal use. The thing is that it should work during the show and I do not want the reservoir to be dissolved. I'll use standard Zortrax printer and know that such part shouldn't be used as a normal part in the car.
We do not have HDPE in use so, do you think the PETG (Polyethylene Terepthalate Glycol) is correct for such thing?

RE: brake fluid reservoir - material

No, not really. But if you want to try, I would print two small plates of the same approximate thickness as your tank wall, and then measure them in all 3 dimensions very accurately and weigh them to the nearest milligram. Then stick one of them in a glass bottle with brake fluid, and set it on a shelf for a week or two. Take it out and measure it (it will probably swell), weigh it (the absorbed fluid will cause the sample weight to increase) and then bend it (compare to the bending resistance of the un-soaked piece, it will probably be weaker and possibly snap). Should tell you quite a bit about its compatibility.

RE: brake fluid reservoir - material

The method to see if it is suitable is to just get a glass jar and pour in some brake fluid and drop in samples of extrusion material - this is how compatibility studies are done. Wait a week or two and see if the items have changed size or dissolved. It helps to weigh them before and after to see if fluid is being absorbed.

According to http://kmac-plastics.net/data/chemical/petg-chemic... it hasn't been tested by them.

There is this: https://discuss.toms3d.org/filaments-f10/filament-...

RE: brake fluid reservoir - material

Great, thanks for help colleagues, I'll try with testing two small examples and measure/weight them before and after using with the fluid. Thank you for help if anyone is interested in results please let me know.

So now just hope the printer manage to print two exact the same samples...

RE: brake fluid reservoir - material

Use enough test material so you can actually see that weight difference.

Keith Cress
kcress - http://www.flaminsystems.com

RE: brake fluid reservoir - material

How is the progress? I would like to the results of your tests.

RE: brake fluid reservoir - material

Hi, as printers available for me are all printing samples for my clients at the moment, I'll start the test on Monday 19.03 so probably about 27-28.03 have results (one week in the fluid should be enough I hope).
I'll let you know when the examine is done.

RE: brake fluid reservoir - material

You don't need a printed sample, just a measured/weighed length of plastic from the printing spool.

Dan - Owner

RE: brake fluid reservoir - material

I understand but we want to see if there is any change in the shape of ready product also...

RE: brake fluid reservoir - material

I'd argue you should test a printed sample, as you don't know what changes might occur in the filament due to the process, but I can theorize quite a few things that could happen, and none of them make the polymer more resistant.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close